Fuel Trims at Idle (Diagram)

GTSHolgi

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I was playing around the other day with my ODBII reader (Autel MS509) just out of curiosity. Car runs fine, no issues ('98 RT/10 stock except for Corsa catback, hiflow cats & smooth tubes). I sampled the Idle mode after driving around for a few miles and then spent some time to create a diagram with the help of excel.

Observations so far:

1. System enters closed loop mode after 30 sec. During open loop mode, STFT is 0 and LTFT is static, where bank 2 seems to run richer than bank 1.
2. When systems enters closed loop mode STFT start to jump back and forth. However, trend seems to be positive for bank 1 and negative for bank 2. That means, that LTFT of bank 1 would increase over time but LTFT of bank 2 would further decrease.

Would you agree to say, that bank 2 seems to run richer than bank 1 and that something is not right because of this? Or is this still in a normal range? Maybe, the measurement was too short to really conclude something? :rolleyes:

I hope someone who has more experience with interpreting this kind of data and can chime in :2tu:

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I see nothing out of the ordinary there. Most cars have trims that are within 10% bank to bank, but rarely are they much closer than 5%. Your car is only a couple percent apart, and that is very good in the scheme of things.
 

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