CSVT#49
Addicted CEG'er
Well one of my first thoughts is this... there are only a few things that drives fuel consumption at the ECM and one is pretty much it's only means of feedback... HEGO (O2) sensors. What's that status of your upper HEGO sensors? If one is reading slighting different then the other I could see that happening. It may be the same mixture front to rear, but if the bank 2 sensor is saying it's running a little leaner then the bank 1 sensor then the ECM will provide more fuel to that bank. Remember you are only dealing with a 0-1V accuracy, which isn't much.