Uneven ltrims
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TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Uneven ltrims Bank1 is running about 7 to 10% more then bank2. My o2 sensors are also uneven about .1 – 2 mvolts, do I have an injector clogged, one going out? Could it be my o2 sensor? At idle my bank1 ltrims runs about 7% and bank2 is almost always .8% to -.8%, if I rev the motor they both go up but stay about 7% apart.
Thanks <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
Thanks <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
Thread Starter
TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: Uneven ltrims I have a small exhaust leaks when the cats where removed, from what I can tell it's after the 1st 02 sensor and the rear sensors has 02 Sims plugged in to them. Could a leak pull air back in to the exhaust and cause this?
I will try to move the bank1 02 sensor to the 2nd bank, I have rear 02’s but they are not same are they? <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
Any other idea’s on what to look for? Any one had a problem like this before?
Thanks for the tips guys <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />
I will try to move the bank1 02 sensor to the 2nd bank, I have rear 02’s but they are not same are they? <img border="0" alt="[Fluffy]" title="" src="graemlins/fluffy.gif" />
Any other idea’s on what to look for? Any one had a problem like this before?
Thanks for the tips guys <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />
TECH Regular
Joined: Nov 2001
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From: Clarkston
Re: Uneven ltrims As Chris said, air leak or bad O2.
A mis-fire condition on Bank 1 could also cause this condition. (cyl miss-fires so the uncombusted air reaches the O2 - commanding more fuel to that bank)
Check your "misfire current" parameter for you cylinders and see what they read. (This parameter reads # of misses per 200 revolutions than resets: Look for 1 that may be up in the 60-70 range at off-idle.
A mis-fire condition on Bank 1 could also cause this condition. (cyl miss-fires so the uncombusted air reaches the O2 - commanding more fuel to that bank)
Check your "misfire current" parameter for you cylinders and see what they read. (This parameter reads # of misses per 200 revolutions than resets: Look for 1 that may be up in the 60-70 range at off-idle.
Thread Starter
TECH Apprentice
Joined: Jan 2002
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From: Princeton, IN
Re: Uneven ltrims i have no misfire's, so does that mean it could only be the o2's or is there something else i can look for? i have no codes in the pcm after about 500 miles.
Thanks <img border="0" title="" alt="[Embarrassed]" src="gr_emb.gif" />
<small>[ April 04, 2002, 08:18 PM: Message edited by: dissonance ]</small>
Thanks <img border="0" title="" alt="[Embarrassed]" src="gr_emb.gif" />
<small>[ April 04, 2002, 08:18 PM: Message edited by: dissonance ]</small>
Re: Uneven ltrims -I thought Ltrims will differ somewhat because they are not located the same distance back from the motor?
-Exhaust leaks will absolutely screw up stuff. Any leak before the 02's will make all readings useless IMO.
-Lazy O2's will make the car run rich. 02 can be lazy from being coated with junk.
-Exhaust leaks will absolutely screw up stuff. Any leak before the 02's will make all readings useless IMO.
-Lazy O2's will make the car run rich. 02 can be lazy from being coated with junk.
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Thread Starter
TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: Uneven ltrims I have not switched them; they are different from my understanding. I talked with a guy at the Chevy dealership and he said I have a bad heater in that o2. The o2 will rage from .9 to .0025 and bounce back and forth. My other bank 2 stays .8 to .4 and goes back and forth. Again I have no freeze frame data in the pcm or codes. The exhaust leak which is minor will be fixed Monday. I have a new o2 sensor from gm but I am going to wait until I get the exhaust fix, after that if the problems stay will try to swap the o2 before I put the new one in.
Please any other ideas before I blow another $117 on an o2 sensor
Please any other ideas before I blow another $117 on an o2 sensor
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Verdad Gallardo Re: Uneven ltrims O2's will switch back and forth, the smaller the range of switching the more messed up they are... a totally messed up one will default to like .445 MV's. 'lazy' o2's don't switch as fast as they should.
Maybe try cleaning your 02's with contact cleaner?
Maybe try cleaning your 02's with contact cleaner?
Thread Starter
TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: Uneven ltrims i have logs from today
they can be found here
http://208.202.224.10/autotap
links right to them
http://208.202.224.10/autotap/ltrims.atl
http://208.202.224.10/autotap/ltrims.csv
i have both the autotap and excel output's
please take a look at these <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" />
they can be found here
http://208.202.224.10/autotap
links right to them
http://208.202.224.10/autotap/ltrims.atl
http://208.202.224.10/autotap/ltrims.csv
i have both the autotap and excel output's
please take a look at these <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" />
Thread Starter
TECH Apprentice
Joined: Jan 2002
Posts: 364
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From: Princeton, IN
Re: Uneven ltrims Yeah in that log I was looking at the wrong one. I have fixed the o2 problem, I also fixed the leak, trims are real close at idle now but they still pull are when I rev the motor or I am running down the road. I don’t think it could be a vacuum leak with only one side going up.
