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The trims are the highest at idle. If you raise the RPM they go down a couple of percent, a few areas are the same as the idle._x000D_
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I said that I already cleaned the MAF – no difference. It was actually perfectly clean to begin with._x000D_
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I’ve done a power bYou might be right Eric. It just seems strange to me that temperature affects the trims so much ( since it shouldn’t)._x000D_
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It concerns me that fuel pressure is out of spec (39 to 40 psi) when the engine is off, but with the engine running it just barely hiFuel delivery IS greatly effected by temperature that’s why they run an air temp sensor to help adjust the fuel trim.
Any updates on this? I’m currently working on a 2000 Echo and the LTFT are showing 29.7 and STFT is showing -20.9, so way out of spec. The car is also throwing P0171 and I have no air leaks and a new MAF has not cleared the issue.
At this point I’m thinking it’s bank 1 sensor 1 o2 sensor as it was replaced recently with a non-Denso unit. Any other ideas?
Any updates on this? I’m currently working on a 2000 Echo and the LTFT are showing 29.7 and STFT is showing -20.9, so way out of spec. The car is also throwing P0171 and I have no air leaks and a new MAF has not cleared the issue.
At this point I’m thinking it’s bank 1 sensor 1 o2 sensor as it was replaced recently with a non-Denso unit. Any other ideas?
[quote=”VR6OhMy” post=100627]Any updates on this? I’m currently working on a 2000 Echo and the LTFT are showing 29.7 and STFT is showing -20.9, so way out of spec. The car is also throwing P0171 and I have no air leaks and a new MAF has not cleared the issue.
At this point I’m thinking it’s bank 1 sensor 1 o2 sensor as it was replaced recently with a non-Denso unit. Any other ideas?[/quote]
Don’t assume it’s an O2 sensor. Many things can effect fuel trim. Several are outlined in this article.
http://www.ericthecarguy.com/faq/solving-automotive-performance-issues
Good luck and keep us posted.
[quote=”VR6OhMy” post=100627]Any updates on this? I’m currently working on a 2000 Echo and the LTFT are showing 29.7 and STFT is showing -20.9, so way out of spec. The car is also throwing P0171 and I have no air leaks and a new MAF has not cleared the issue.
At this point I’m thinking it’s bank 1 sensor 1 o2 sensor as it was replaced recently with a non-Denso unit. Any other ideas?[/quote]
Don’t assume it’s an O2 sensor. Many things can effect fuel trim. Several are outlined in this article.
http://www.ericthecarguy.com/faq/solving-automotive-performance-issues
Good luck and keep us posted.
Hey Eric…
So far I’ve replaced the IM gasket for good measure as the car has almost 200k with no service history on it. The gasket was indeed hard and not very pliable.
I’ve also replaced the MAF after registering a max of 80 load at full throttle.
There are no other air leaks, on the intake or exhaust side of things, which is why I’m thinking it’s the non-denso o2 sensors. What do you think based on that info?
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