AK <scienti...@gmail.com> wrote:
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?If your O2 sensor was reading low and causing the computer to run the
engine too rich, then yes.
But it all depends on what kind of engine it is and what kind of
control system came with it and how the sensor failed.
--scott
--Thanks Scott.
"C'est un Nagra. C'est suisse, et tres, tres precis."
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
AK <scientist77017@gmail.com> wrote:
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
If your O2 sensor was reading low and causing the computer to run the
engine too rich, then yes.
But it all depends on what kind of engine it is and what kind of
control system came with it and how the sensor failed.
--scott
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com
(Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
If your O2 sensor was reading low and causing the computer to run the >>engine too rich, then yes.
So if now I get codes P0171 and P0174, which means that both banks are >running lean, does that mean replacing the sensors will cause the
opposite of what AK had, richer mixturen and decreased mpg?
micky <NONONOmisc07@fmguy.com> wrote:
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com
(Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are
I had an oxygen sensor replaced.If your O2 sensor was reading low and causing the computer to run the
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
engine too rich, then yes.
running lean, does that mean replacing the sensors will cause the
opposite of what AK had, richer mixturen and decreased mpg?
Scott Dorsey wrote:
micky <NONONOmisc07@fmguy.com> wrote:
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com
(Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are
I had an oxygen sensor replaced.If your O2 sensor was reading low and causing the computer to run the
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
engine too rich, then yes.
running lean, does that mean replacing the sensors will cause the
opposite of what AK had, richer mixturen and decreased mpg?
Changing the sensors will do nothing but show the same codes again.
Those codes you posted mean the sensors are working. They are seeing
that there is excess oxygen in the exhaust stream compared to what they >expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for
vacuum leaks or an intake leak that is letting in unmetered air.
As you don't post any P0300 range codes I doubt it's fuel pressure as
that will commonly set misfire codes as well as the lean codes.
micky wrote:
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W."
<csr684@NOTyahoo.com> wrote:
Scott Dorsey wrote:I did buy a code reader last year that would read the live data, but
micky <NONONOmisc07@fmguy.com> wrote:Changing the sensors will do nothing but show the same codes again.
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com
(Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are >>>>> running lean, does that mean replacing the sensors will cause the
I had an oxygen sensor replaced.If your O2 sensor was reading low and causing the computer to run the >>>>>> engine too rich, then yes.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
opposite of what AK had, richer mixturen and decreased mpg?
Those codes you posted mean the sensors are working. They are seeing
that there is excess oxygen in the exhaust stream compared to what they
expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for
what I should look for has been mostly a mystery since then, until the
video below. I found it a few days ago but just had time to watch it.
Cars are much more complicated than when I was a boy, or even a
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a
lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.Thanks. I found a long video that went over at least some of the
As you don't post any P0300 range codes I doubt it's fuel pressure as
that will commonly set misfire codes as well as the lean codes.
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU
He ended up finding a leaky brake booster and a somewhat bad MAF sensor,
but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this
video. I miss the days when there were people here who knew less than I
do. They woudl benefit more from this post than you or the others here
will.
I don't know everything but I'm pretty good at diagnostic and repair
work on vehicles.
How much do you really want to know about modern engine diagnostics?
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W." <csr684@NOTyahoo.com> wrote:
Scott Dorsey wrote:
micky <NONONOmisc07@fmguy.com> wrote:
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com
(Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are >>>> running lean, does that mean replacing the sensors will cause the
I had an oxygen sensor replaced.If your O2 sensor was reading low and causing the computer to run the >>>>> engine too rich, then yes.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
opposite of what AK had, richer mixturen and decreased mpg?
Changing the sensors will do nothing but show the same codes again.
Those codes you posted mean the sensors are working. They are seeing
that there is excess oxygen in the exhaust stream compared to what they
expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for
I did buy a code reader last year that would read the live data, but
what I should look for has been mostly a mystery since then, until the
video below. I found it a few days ago but just had time to watch it.
Cars are much more complicated than when I was a boy, or even a
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a
lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.
As you don't post any P0300 range codes I doubt it's fuel pressure as
that will commonly set misfire codes as well as the lean codes.
Thanks. I found a long video that went over at least some of the
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU
He ended up finding a leaky brake booster and a somewhat bad MAF sensor,
but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this
video. I miss the days when there were people here who knew less than I
do. They woudl benefit more from this post than you or the others here
will.
Steve W. wrote:
micky wrote:
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W."
<csr684@NOTyahoo.com> wrote:
Scott Dorsey wrote:
micky <NONONOmisc07@fmguy.com> wrote:
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com >>>>>> (Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are >>>>>> running lean, does that mean replacing the sensors will cause the
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor? >>>>>>> If your O2 sensor was reading low and causing the computer to run the >>>>>>> engine too rich, then yes.
opposite of what AK had, richer mixturen and decreased mpg?
Changing the sensors will do nothing but show the same codes again.
Those codes you posted mean the sensors are working. They are seeing
that there is excess oxygen in the exhaust stream compared to what they >>>> expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for
I did buy a code reader last year that would read the live data, but
what I should look for has been mostly a mystery since then, until the
video below. I found it a few days ago but just had time to watch it.
Cars are much more complicated than when I was a boy, or even a
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a
lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.
As you don't post any P0300 range codes I doubt it's fuel pressure as
that will commonly set misfire codes as well as the lean codes.
Thanks. I found a long video that went over at least some of the
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU
He ended up finding a leaky brake booster and a somewhat bad MAF sensor, >>> but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this
video. I miss the days when there were people here who knew less than I >>> do. They would benefit more from this post than you or the others here
will.
I don't know everything but I'm pretty good at diagnostic and repair
work on vehicles.
How much do you really want to know about modern engine diagnostics?
Oh where he is checking the hoses, a quick trick is to use carb cleaner
and spray it around the hoses. If the engine rpm suddenly jumps look in
the area you were spraying for a leak.
In alt.home.repair, on Wed, 07 Apr 2021 20:24:26 -0400, "Steve W." ><csr684@NOTyahoo.com> wrote:
Steve W. wrote:
micky wrote:
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W."
<csr684@NOTyahoo.com> wrote:
Scott Dorsey wrote:
micky <NONONOmisc07@fmguy.com> wrote:
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com >>>>>>> (Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are >>>>>>> running lean, does that mean replacing the sensors will cause the >>>>>>> opposite of what AK had, richer mixturen and decreased mpg?
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor? >>>>>>>> If your O2 sensor was reading low and causing the computer to run the >>>>>>>> engine too rich, then yes.
Changing the sensors will do nothing but show the same codes again.
Those codes you posted mean the sensors are working. They are seeing >>>>> that there is excess oxygen in the exhaust stream compared to what they >>>>> expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for
I did buy a code reader last year that would read the live data, but
what I should look for has been mostly a mystery since then, until the >>>> video below. I found it a few days ago but just had time to watch it. >>>>
Cars are much more complicated than when I was a boy, or even a
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a >>>> lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.
As you don't post any P0300 range codes I doubt it's fuel pressure as >>>>> that will commonly set misfire codes as well as the lean codes.
Thanks. I found a long video that went over at least some of the
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU
I made a lot notes based on what he said.
He ended up finding a leaky brake booster and a somewhat bad MAF sensor, >>>> but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this
video. I miss the days when there were people here who knew less than I >>>> do. They would benefit more from this post than you or the others here >>>> will.
I don't know everything but I'm pretty good at diagnostic and repair
work on vehicles.
How much do you really want to know about modern engine diagnostics?
Just enough to fix my car, and maybe a little more. :-)
I used the scanner today and the short and long term trims tracked the >results of the guy who made the video, at idle and up to 2500rpm. Also
the MAF value (in metric) and the ECT, Spark, Load, and IAT seemed on
track. Mine starts at OL and goes quickly to CL for both banks.
I forgot to look at the 02BnSn, but I think they're stored in the
scanner. Yes, I posted them below, if that's what Review refers to.
The scanner is inside with me, but the notes are in the car. I'll post
them here later.
Oh where he is checking the hoses, a quick trick is to use carb cleaner
and spray it around the hoses. If the engine rpm suddenly jumps look in
the area you were spraying for a leak.
He sprayed with water, hoping to hear a hiss, but not with carb clean.
I was going to spray with brake cleaner, because it says No Residue, but >maybe carb cleaner is better? (He didn't say why not, not a word about >spraying with other things.)
If that doesn't find it (and I did look everywhere I could think of last >year, using propane), I'm going to disconnect the purge solenoid and
plug that hose, and then disconnect the brake booster and plug that one,
the hoses that go into the throttle body. That's how he found a major >problem with his brake booster.
He used a vacuum tester to plug each hose in turn that goes to the
throttle body, but seems to me I don't need a tester. I can assume
there is some vacuum if the engine is running and it doesn't matter how
much, and all I need to do is use a pencil or something bigger to plug
each hose.
Last time when I was trying to find a vacuum leak, I didn't know and
didn't think about the fact that some leaks don't go to the outside,
like a leak in a hose does. He didn't name anything other than the
cannister circuit** and the brake booster that could have an internal
vacuum leak. There are so many hoses, I dont' have much confidence I
would think of something else even if it exists. Are there other things
I should disconnect? **The cannister circuit of couree includes a
long hose almost to the gas tank, which he couldn't feel or spray or
look at.
Fixing the brake booster lowered his trim total by 30 points but it was
still too high. He found that his MAF sensor was off somewhat and after
he replaced that too, everything was good. (Trim total was between +10
and -10.) I replaced my MAF sensor about 10,000 miles ago, on the hope
that would fix things. I only used a mimimal code reader th1en so if it
made any difference, I don't know, but it didn't get rid of the codes
and, I doubt if it's the problem now. AND today, I don't want to guess
what my MAF was at idle, but I know it was 9.5 at 2500RPM. His original
one started at idle (cold) 0.57 to idle (warm) 1.84, g/sec (and he said
2 to 3 would be better), but even at 2500 rpm, his value would never go
over 7 or 8, so I think mine works better. At least I think so.
I'm not sure what I see when I go to Review / Live Data / Location #1
(the only one listed). IIUC, the data there is from this afternooon and
it says
DTC_CNT is 2. That makes sense, P0171 and P0174.
02B1S2(v) is 0.680
B2 is 0.680 also
O2B1S1 is 3.279
02B2S1 is 3.250 very similar to bank 1
He had said that 3.3 is perfect 14.7 to 1, air to fuel ratio. My
two numbers are pretty close but maybe they'd be closer to 3.3 if ...
EQ_RATB2S1 is 0.988 but I don't know what that means and he didn't say,
and I havent' taken the time to look it up yet.
B1S1 is 1.006, very similar.
SHRTFTB1S2 is N/A.
while
SHRTFTB2S2 is 99.2 Isn't that strange? In the 4 values 8 lines up,
B1S2 and B2S2 are exactly the same. there something wrong with B1S2?
02SLOC is B1S12--B2S12-- whatever that means.
I hope I didn't give too much info.
I used the scanner today and the short and long term trims tracked the >>results of the guy who made the video, at idle and up to 2500rpm. Also
An important thing I left out was that he said "When we raise RPM to
2000, does SHRT [short term trim] get better, or worse, or the same? If it gets better,
lower, usually a vacuum leak."
It got lower for him. And for me, it went up a little at first but then
went down somewhere between quite a bit and a lot. Numbers, if any, are
in the car.
More than one value I saw go in two different directions, and in other >aspects of my life, a little bit in one direction at first and much more
in the other direction soon after. I think he mentioned that too.
So so far it's looking like a vacuum leak.
Maybe no need to replace either 02 sensor, especially the one behind
the engine. OTOH, I've read that they fail with age or miles. 70,000, >100,000 were mentioned and I have 140,000.
Steve W. wrote:
micky wrote:Oh where he is checking the hoses, a quick trick is to use carb cleaner
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W."I don't know everything but I'm pretty good at diagnostic and repair
<csr684@NOTyahoo.com> wrote:
Scott Dorsey wrote:what I should look for has been mostly a mystery since then, until the
micky <NONONOmisc07@fmguy.com> wrote:Changing the sensors will do nothing but show the same codes again.
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com >>>>>> (Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are >>>>>> running lean, does that mean replacing the sensors will cause the
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor? >>>>>>> If your O2 sensor was reading low and causing the computer to run the >>>>>>> engine too rich, then yes.
opposite of what AK had, richer mixturen and decreased mpg?
Those codes you posted mean the sensors are working. They are seeing
that there is excess oxygen in the exhaust stream compared to what they >>>> expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for >>> I did buy a code reader last year that would read the live data, but
video below. I found it a few days ago but just had time to watch it.
Cars are much more complicated than when I was a boy, or even a
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a
lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.Thanks. I found a long video that went over at least some of the
As you don't post any P0300 range codes I doubt it's fuel pressure as
that will commonly set misfire codes as well as the lean codes.
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU >>>
He ended up finding a leaky brake booster and a somewhat bad MAF sensor, >>> but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this
video. I miss the days when there were people here who knew less than I >>> do. They woudl benefit more from this post than you or the others here
will.
work on vehicles.
How much do you really want to know about modern engine diagnostics?
and spray it around the hoses. If the engine rpm suddenly jumps look in
the area you were spraying for a leak.
On Thursday, April 8, 2021 at 2:05:17 AM UTC-4, Steve W. wrote:
Steve W. wrote:
Steve W. wrote:From what you posted you have a vacuum leak/pirate air issue as the
micky wrote:Oh where he is checking the hoses, a quick trick is to use carb cleaner
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W."I don't know everything but I'm pretty good at diagnostic and repair
<csr...@NOTyahoo.com> wrote:
Scott Dorsey wrote:what I should look for has been mostly a mystery since then, until the >> >>> video below. I found it a few days ago but just had time to watch it.
micky <NONONO...@fmguy.com> wrote:Changing the sensors will do nothing but show the same codes again.
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, klu...@panix.com
(Scott Dorsey) wrote:
AK <scienti...@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are
I had an oxygen sensor replaced.If your O2 sensor was reading low and causing the computer to run the
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor?
engine too rich, then yes.
running lean, does that mean replacing the sensors will cause the
opposite of what AK had, richer mixturen and decreased mpg?
Those codes you posted mean the sensors are working. They are seeing
that there is excess oxygen in the exhaust stream compared to what they >> >>>> expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for >> >>> I did buy a code reader last year that would read the live data, but
Cars are much more complicated than when I was a boy, or even a
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a >> >>> lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.Thanks. I found a long video that went over at least some of the
As you don't post any P0300 range codes I doubt it's fuel pressure as >> >>>> that will commonly set misfire codes as well as the lean codes.
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU >> >>>
He ended up finding a leaky brake booster and a somewhat bad MAF sensor, >> >>> but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this
video. I miss the days when there were people here who knew less than I >> >>> do. They woudl benefit more from this post than you or the others here >> >>> will.
work on vehicles.
How much do you really want to know about modern engine diagnostics?
and spray it around the hoses. If the engine rpm suddenly jumps look in
the area you were spraying for a leak.
primary problem. You can use brake clean or carb cleaner, they are both
more or less paint thinners that burn ok. I use carb cleaner because the
older version of brake cleaner is chlorinated and generates toxic gas
when burned.
The thing to remember though is that in the video he is working on a car
different than yours, some things apply, others don't. For instance MAF
flow, as engine sizes go up, MAF numbers increase even at idle to feed
the larger engine.
Try this
https://support.alldata.com/sites/main/files/file-attachments/maf_sensor_testing_110918.pdf
Looking at the fuel trims that go up, then start coming down means that
it's a medium sized leak. As the throttle opens it goes past the point
where the pirate air is the main component and the mixture improves. If
it started improving immediately it would be a small leak.
For the sensor data you want to look at it live, and watch what it
actually reads, if the front sensors are changing voltages rapidly > the engine runs and the rear sensors stay at a somewhat constant number
and don't vary like the fronts, the sensors are working and although
they may be worn, they are doing their job and the converters are working. >> You may be surprised at where a vacuum leak can be, brake booster, PCV
system, intake manifold gaskets, a damaged port on the manifold, in the
EVAP system and a host of others, some external others internal.
OH the wuse of water for leaks is somewhat common, it's because you can
use it on a hot or cold engine or one where you have ignition sources
like open plug wires or bad coils. The amount of cleaner you will use
won't be an issue though, just be sure to start on a cold engine.
Usually something like an intake leak will get better as the engine
warms up so you want to catch it when it's cold.
--
Steve W.
Since he's fiddled around looking for a vacuum leak for awhile already and can't
find an obvious one, I'd suggest getting a schematic that shows all the vacuum lines.
Then it will be easier to figure out where they tap off from, how to separate that
section and plug it.
Or try the smoke tester.
I've never used one, but have read of
other people using them and sounds like in principle it would work.
Steve W. wrote:
Steve W. wrote:
micky wrote:Oh where he is checking the hoses, a quick trick is to use carb cleaner
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W."I don't know everything but I'm pretty good at diagnostic and repair
<csr684@NOTyahoo.com> wrote:
Scott Dorsey wrote:what I should look for has been mostly a mystery since then, until the >>>> video below. I found it a few days ago but just had time to watch it. >>>>
micky <NONONOmisc07@fmguy.com> wrote:Changing the sensors will do nothing but show the same codes again.
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com >>>>>>> (Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are >>>>>>> running lean, does that mean replacing the sensors will cause the >>>>>>> opposite of what AK had, richer mixturen and decreased mpg?
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor? >>>>>>>> If your O2 sensor was reading low and causing the computer to run the >>>>>>>> engine too rich, then yes.
Those codes you posted mean the sensors are working. They are seeing >>>>> that there is excess oxygen in the exhaust stream compared to what they >>>>> expect based on the incoming airflow numbers.
The issue is not them but in the engine. As both are full bank lean
codes I would look at the fuel trims and the O2 live data and check for >>>> I did buy a code reader last year that would read the live data, but
Cars are much more complicated than when I was a boy, or even a
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a >>>> lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.Thanks. I found a long video that went over at least some of the
As you don't post any P0300 range codes I doubt it's fuel pressure as >>>>> that will commonly set misfire codes as well as the lean codes.
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU >>>>
He ended up finding a leaky brake booster and a somewhat bad MAF sensor, >>>> but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this
video. I miss the days when there were people here who knew less than I >>>> do. They woudl benefit more from this post than you or the others here >>>> will.
work on vehicles.
How much do you really want to know about modern engine diagnostics?
and spray it around the hoses. If the engine rpm suddenly jumps look in
the area you were spraying for a leak.
From what you posted you have a vacuum leak/pirate air issue as the
primary problem. You can use brake clean or carb cleaner, they are both
more or less paint thinners that burn ok. I use carb cleaner because the >older version of brake cleaner is chlorinated and generates toxic gas
when burned.
The thing to remember though is that in the video he is working on a car >different than yours, some things apply, others don't. For instance MAF
flow, as engine sizes go up, MAF numbers increase even at idle to feed
the larger engine.
Try this >https://support.alldata.com/sites/main/files/file-attachments/maf_sensor_testing_110918.pdf
Looking at the fuel trims that go up, then start coming down means that
it's a medium sized leak. As the throttle opens it goes past the point
where the pirate air is the main component and the mixture improves. If
it started improving immediately it would be a small leak.
For the sensor data you want to look at it live, and watch what it
actually reads, if the front sensors are changing voltages rapidly as
the engine runs and the rear sensors stay at a somewhat constant number
and don't vary like the fronts, the sensors are working and although
they may be worn, they are doing their job and the converters are working. >You may be surprised at where a vacuum leak can be, brake booster, PCV >system, intake manifold gaskets, a damaged port on the manifold, in the
EVAP system and a host of others, some external others internal.
OH the wuse of water for leaks is somewhat common, it's because you can
use it on a hot or cold engine or one where you have ignition sources
like open plug wires or bad coils. The amount of cleaner you will use
won't be an issue though, just be sure to start on a cold engine.
Usually something like an intake leak will get better as the engine
warms up so you want to catch it when it's cold.
Or try the smoke tester.
I think we talked about this last year, but I was not despairing yet.
They have one for sale for 100, another for 120, and one for 900. WRT >rental, autozone and advance don't have it, but there was a PepBoys
page, so I called the local Pepboys and he knew almost nothing about it.
I called maybe a bigger Pepboys and he didnt' either but he asked
someone and indded they have such a machine. He didn't even know how
much it costs, but the web page said $30. Well worth it if it works. I
hope they have someone there who stills knows how to use it. And they
want two hours. Maybe more. I guess I can just go and keep busy.
I've never used one, but have read of
other people using them and sounds like in principle it would work.
Yes, it does.
In alt.home.repair, on Thu, 08 Apr 2021 22:46:39 -0400, micky <NONONOmisc07@fmguy.com> wrote:
Or try the smoke tester.
I think we talked about this last year, but I was not despairing yet.
They have one for sale for 100, another for 120, and one for 900. WRT >>rental, autozone and advance don't have it, but there was a PepBoys
page, so I called the local Pepboys and he knew almost nothing about it.
I called maybe a bigger Pepboys and he didnt' either but he asked
someone and indded they have such a machine. He didn't even know how
much it costs, but the web page said $30. Well worth it if it works. I >>hope they have someone there who stills knows how to use it. And they >>want two hours. Maybe more. I guess I can just go and keep busy.
I've never used one, but have read of
other people using them and sounds like in principle it would work.
Yes, it does.
There certainly are a lot of videos about car repair. I haven't watched
it yet but this one is about how to make your own smoke machine! "Easy
and fun to build" What could be better than that.
I'm sure it's satisfying to make a good video and have
people watch it, but do they also make money somehow?
In alt.home.repair, on Thu, 08 Apr 2021 22:46:39 -0400, micky <NONONOmisc07@fmguy.com> wrote:
Or try the smoke tester.I think we talked about this last year, but I was not despairing yet.
They have one for sale for 100, another for 120, and one for 900. WRT
rental, autozone and advance don't have it, but there was a PepBoys
page, so I called the local Pepboys and he knew almost nothing about it.
I called maybe a bigger Pepboys and he didnt' either but he asked
someone and indded they have such a machine. He didn't even know how
much it costs, but the web page said $30. Well worth it if it works. I
hope they have someone there who stills knows how to use it. And they
want two hours. Maybe more. I guess I can just go and keep busy.
I've never used one, but have read ofYes, it does.
other people using them and sounds like in principle it would work.
There certainly are a lot of videos about car repair. I haven't watched
it yet but this one is about how to make your own smoke machine! "Easy
and fun to build" What could be better than that.
I'm sure it's satisfying to make a good video and have people watch it,
but do they also make money somehow?
In rec.autos.tech, on Thu, 08 Apr 2021 02:05:14 -0400, "Steve W." <csr684@NOTyahoo.com> wrote:
Steve W. wrote:
Steve W. wrote:From what you posted you have a vacuum leak/pirate air issue as the
micky wrote:Oh where he is checking the hoses, a quick trick is to use carb cleaner
In rec.autos.tech, on Sat, 03 Apr 2021 02:07:24 -0400, "Steve W."I don't know everything but I'm pretty good at diagnostic and repair
<csr684@NOTyahoo.com> wrote:
Scott Dorsey wrote:Cars are much more complicated than when I was a boy, or even a
micky <NONONOmisc07@fmguy.com> wrote:Changing the sensors will do nothing but show the same codes again. >>>>>> Those codes you posted mean the sensors are working. They are seeing >>>>>> that there is excess oxygen in the exhaust stream compared to what they >>>>>> expect based on the incoming airflow numbers.
In rec.autos.tech, on 27 Mar 2021 19:31:15 -0000, kludge@panix.com >>>>>>>> (Scott Dorsey) wrote:
AK <scientist77017@gmail.com> wrote:So if now I get codes P0171 and P0174, which means that both banks are >>>>>>>> running lean, does that mean replacing the sensors will cause the >>>>>>>> opposite of what AK had, richer mixturen and decreased mpg?
I had an oxygen sensor replaced.
Prior to that I got 20 mpg in the city for my CX7.
Now I am getting 21.5 mpg.
Could that increase be due to the replacement of the O2 sensor? >>>>>>>>> If your O2 sensor was reading low and causing the computer to run the >>>>>>>>> engine too rich, then yes.
The issue is not them but in the engine. As both are full bank lean >>>>>> codes I would look at the fuel trims and the O2 live data and check for >>>>> I did buy a code reader last year that would read the live data, but >>>>> what I should look for has been mostly a mystery since then, until the >>>>> video below. I found it a few days ago but just had time to watch it. >>>>>
teenager, and I've said for years and told quite a few people that
anyone smart enough to be a good mechanic these days could succeed in a >>>>> lot of fields.
vacuum leaks or an intake leak that is letting in unmetered air.Thanks. I found a long video that went over at least some of the
As you don't post any P0300 range codes I doubt it's fuel pressure as >>>>>> that will commonly set misfire codes as well as the lean codes.
things to do with a P0171. https://www.youtube.com/watch?v=SugtR4KMIDU >>>>>
He ended up finding a leaky brake booster and a somewhat bad MAF sensor, >>>>> but more importantly he goes into some detail about what everything
means.
You and some of the other people here know everything that is in this >>>>> video. I miss the days when there were people here who knew less than I >>>>> do. They woudl benefit more from this post than you or the others here >>>>> will.
work on vehicles.
How much do you really want to know about modern engine diagnostics?
and spray it around the hoses. If the engine rpm suddenly jumps look in
the area you were spraying for a leak.
primary problem. You can use brake clean or carb cleaner, they are both
more or less paint thinners that burn ok. I use carb cleaner because the
older version of brake cleaner is chlorinated and generates toxic gas
when burned.
Oops, I don't want that. I ordered it online and haven't gotten it yet,
but it also says the original version is not flammable (unlike the other three versions in green cans, without chlorine),
So how could it work at all if it's not flammable?
There's a chart about a fifth of the way down, comparing 5 different
version of Brakleen. Only in the red can is there chlorine but only that
one is Not Flammable! https://www.amazon.com/CRC-05089-BRAKLEEN-Brake-Cleaner/dp/B000LDR9HI/ref=psdc_15718981_t1_B000BXKZUQ
But in videos I watched, they're using Brakleen in that red can! Life
is so complicated.
The thing to remember though is that in the video he is working on a car
different than yours, some things apply, others don't. For instance MAF
flow, as engine sizes go up, MAF numbers increase even at idle to feed
the larger engine.
Yes, I see. The engine he's working on is only 4 cylinders. Mine is 6.
Try this
https://support.alldata.com/sites/main/files/file-attachments/maf_sensor_testing_110918.pdf
I'll print this and do as he says tomorrow.
Looking at the fuel trims that go up, then start coming down means that
it's a medium sized leak. As the throttle opens it goes past the point
where the pirate air is the main component and the mixture improves. If
it started improving immediately it would be a small leak.
Yes, I see.
For the sensor data you want to look at it live, and watch what it
actually reads, if the front sensors are changing voltages rapidly as
the engine runs and the rear sensors stay at a somewhat constant number
and don't vary like the fronts, the sensors are working and although
they may be worn, they are doing their job and the converters are working. >> You may be surprised at where a vacuum leak can be, brake booster, PCV
system, intake manifold gaskets, a damaged port on the manifold, in the
EVAP system and a host of others, some external others internal.
I'll keep looking and look again at places I've looked.
OH the wuse of water for leaks is somewhat common, it's because you can
use it on a hot or cold engine or one where you have ignition sources
like open plug wires or bad coils. The amount of cleaner you will use
won't be an issue though, just be sure to start on a cold engine.
Usually something like an intake leak will get better as the engine
warms up so you want to catch it when it's cold.
Okay.
micky wrote:
In alt.home.repair, on Thu, 08 Apr 2021 22:46:39 -0400, micky <NONONOmisc07@fmguy.com> wrote:
Or try the smoke tester.I think we talked about this last year, but I was not despairing yet.
They have one for sale for 100, another for 120, and one for 900. WRT
rental, autozone and advance don't have it, but there was a PepBoys
page, so I called the local Pepboys and he knew almost nothing about it. >> I called maybe a bigger Pepboys and he didnt' either but he asked
someone and indded they have such a machine. He didn't even know how
much it costs, but the web page said $30. Well worth it if it works. I >> hope they have someone there who stills knows how to use it. And they
want two hours. Maybe more. I guess I can just go and keep busy.
I've never used one, but have read ofYes, it does.
other people using them and sounds like in principle it would work.
There certainly are a lot of videos about car repair. I haven't watched
it yet but this one is about how to make your own smoke machine! "Easy
and fun to build" What could be better than that.
I'm sure it's satisfying to make a good video and have people watch it,
but do they also make money somehow?
A smoke machine is handy but you can do the same testing on a running
car with a can of carb cleaner. The idea with the smoke is that it will pressurize everything and the smoke leaks out, It won't show internal
leaks though.
I built a paint can style a long time ago, it works. For a cheap smoker
you don't need much really, just a can to hold a smoldering fuel source
a hose to connect to the vehicle and a small air source to push the
smoke. Even a cheap aquarium pump will do that. You want between 1/2 and
1 psi of pressure as higher pressures can damage EVAP parts. A cheap way
to get that is a BBQ regulator. Fuel wise I've seen people use the same materials that beekeepers put in their smokers, and even seen people rig those up to work as well.
On Fri, 09 Apr 2021 01:57:23 -0400, Steve W. posted for all of us to digest...
micky wrote:
In alt.home.repair, on Thu, 08 Apr 2021 22:46:39 -0400, mickyA smoke machine is handy but you can do the same testing on a running
<NONONOmisc07@fmguy.com> wrote:
There certainly are a lot of videos about car repair. I haven't watchedOr try the smoke tester.I think we talked about this last year, but I was not despairing yet.
They have one for sale for 100, another for 120, and one for 900. WRT >>>> rental, autozone and advance don't have it, but there was a PepBoys
page, so I called the local Pepboys and he knew almost nothing about it. >>>> I called maybe a bigger Pepboys and he didnt' either but he asked
someone and indded they have such a machine. He didn't even know how
much it costs, but the web page said $30. Well worth it if it works. I >>>> hope they have someone there who stills knows how to use it. And they >>>> want two hours. Maybe more. I guess I can just go and keep busy.
I've never used one, but have read ofYes, it does.
other people using them and sounds like in principle it would work.
it yet but this one is about how to make your own smoke machine! "Easy
and fun to build" What could be better than that.
I'm sure it's satisfying to make a good video and have people watch it,
but do they also make money somehow?
car with a can of carb cleaner. The idea with the smoke is that it will
pressurize everything and the smoke leaks out, It won't show internal
leaks though.
I built a paint can style a long time ago, it works. For a cheap smoker
you don't need much really, just a can to hold a smoldering fuel source
a hose to connect to the vehicle and a small air source to push the
smoke. Even a cheap aquarium pump will do that. You want between 1/2 and
1 psi of pressure as higher pressures can damage EVAP parts. A cheap way
to get that is a BBQ regulator. Fuel wise I've seen people use the same
materials that beekeepers put in their smokers, and even seen people rig
those up to work as well.
You don't want smoke that will ruin sensors and cause more problems & $$$$
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