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Old 01-27-2013, 03:56 AM   #40
Registered User
Join Date: Jan 2012
Location: Nashville, Tennessee
Posts: 2,107
My Ride: 2002 330ci
the long term fuel trims are still running +8.59%. Thats down from +11.72% i had the other day. showing lean making it run rich?

Still high.....i would like it to be where you said. around 2 or 3

torque pro is showing the 171 and 174 codes.

if the oxygen sensors are telling the computer that there is excess oxygen in the system.....and the computer is adding fuel to compensate running up the fuel trim to a +8.59 or even +11.72 because it thinks there is a lean condition based on the o2 sensors information. then wouldnt the o2 sensors be reading a constant or average lean condition? hanging mostly around a lower range. i see them pretty balanced between 1 and 8. but like you said. the post cats look like they are reporting rich. shouldnt they be reporting lean as well to get the computer to compensate by adding fuel.
the post cats running higher voltage. wouldnt that tell the computer to start taking away fuel and run the fuel trims more towards 0.
Does the 02 sensor follow short term fuel trim? I also will look for where short erm fuel trim is going so much into the + side to make such a high LTFT. typically STFT was pretty balanced

i did read that the MAF should produce 1 gram per liter ....per 500 rpm as a rule of thumb. if that is the case then 4 grams at 700 or 800 rpm sounds about right. looking at the graph for the maf is another story. i only know what it should look like when i floor in it should shoot up. and at idle it should run in neutral between 4 and 5g/sec.....and now know that loaded it should be around 7. the cruising speeds are harder to judge. ive had a hard time where i have a flat spot where i can run 35 to 40. there are a lot of hills around here.

i will have the ltft and stft at idle and the 40 - 55 tomorrow

Could this be a weak fuel pump upon acceleration
Small vacuum leak
Clogged injector
Injector o rings

Last edited by glhx; 01-27-2013 at 05:42 PM.
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