I've made another post about this but got no response, but I think I've traced it down a little. My car runs GREAT when I first start it up. Putting it into reverse/neutral/drive doesn't even phase it. But once the car warms up, for example, if I put it into reverse, it really bogs down and nearly dies. Then it really chugs while I'm backing up.

I'm leaning towards it being a problem with my O2 sensors. However, it is not throwing any codes. Also, after the car is warmed up, sometimes it will really struggle to make power at low rpms. Then if I give it 50% or more throttle, it'll pull out of it and run fine for a bit. Does this seem like a problem with the O2s?

When my car had a misfire (caused by plug wires), my PCM was throwing the right O2 code. We replaced the right O2 with a brand new one, which we had to extend the wires on due to my headers. It seems to work ok and acts mostly normal. It's hard for me to scan with my laptop though because I can't seem to get a stable connection between it and my PCM.

I've tried using different software, different PCs, and the cable tested fine. Does it sound like there is also a wiring issue within my car? Would that casue my problem? Or does this sound like O2s?

Reaally needing some help on this one...

 

Reading some other threads, I decided to disconnect my O2s and it runs fine all the time now. Hmm....

 

Its the 02's.

Is it not throwing codes, or just not throwing the check engine light?

I had the same symptoms as you, with no ses, but When I scanned the car with my laptop, a bad 02 code showed. I replaced it, everything is good

 

It's not throwing either. I scanned it with my laptop as well... hmm. I'll probably just replace them both soon.

 

You are probably ok on the 02's. It's just a matter of closed loop tuning I would bet.