Hello, I've been struggling with my car for the last few days. It seems that the steps i'm taking to get my blm's down are not working. My car is an 86 trans am 355 with 268xfi roller cam, stock lower intake, slp runners, and a ported throttle body. I've upgraded from a 1 wire o2 to a 3 wire thinking that it was reading cold with my headers, but the readings stayed the same. They seem to be ok at idle and under accel, but at cruise they are pegged at 160 even though the wb i have is reading around 12.5-13.2. I've found that my troubles are in cells 6, 10, 11, 14, and 15. I'm using tuner pro rt with a 6e.xdf and 1227165_6e.adx. I'll try to attach my latest log file and add .txt at the end if that will help. Thanks guys

 

start looking for a vacuum leak

 

ECM uses feedback from the NB O2 sensor to adjust the INT & BLM. With the WB reporting a richer then stoich mix, if it is correct, then there is something wrong with the NB signal.

It could be an exhaust leak affecting it, a bad O2 sensor ground, or the ECM itself.

RBob.

 

I don't hear or see any exhaust leaks, and its a new sensor right in the collector of the left header. I'll get a new pcm since mine is under warranty and see if that changes anything. Thanks for the advice.

 

My evap cannister was unplugged once and caused this problem.. Must have hit it off while working on something else and it was driving me nuts. I just plugged it back in and problem solved.

How did you wire your 3 wire O2 sensor?

 

It's an afs-74 the purple wire went to the stock o2 wire and as for the other two I have one hooked to a switched 12v and the other ran to the battery for ground. And for the canister all the lines are plugged in. One goes back to the tank one to vacuum at the t-body and the other is a fresh air on the side of the t-body