You said "scanner showed really low millivolts (rich) at o2 sensors ( they were reading and adjusting but could not get it above 400 millvolts" . That's lean and they will add fuel, 450Mv average is close to normal, as they cycle between 100-900 Mv. Under 450 average is lean. So your PCM is adding fuel. Not sure about the MAP, the PCM seeing false high vacuum (low Kpa) at low RPM could see that as deceleration and start pulling fuel, just a thought. Sure wish you had TTS DataMaster, it's free for 20 logs, helps tremendously in problems like this. Also freescan is free. By the way your FP is a little higher than normal, it's usually high 30's at idle and goes up +5 lbs when vacuum is removed from the regulator. Doesn't seem off enough to cause your problems.
I'm Bob.. 1994 Z28, A4, Stall, CAI, Cam, RR's, 342 rear, LT's , CatBack, Tuned
Last edited by bobdec; 02-17-2012 at 10:37 PM.