so i traded my 95 a4 for a 97 m6 last week. the 97 has a fresh 355 with an lt4 hotcam. the guy just had the motor on the mounts so i had to wire it and add a few parts. i got the car running today and it runs like crap. veryyy rich. i was running open headers at the time so im guessing the o2 sensors would be causing this. correct? im not getting an ses light yet so im not sure.

 

Has the motor been tuned to run with the LT4 hotcam? How do you know it's running rich? Is "running like crap" part of the "running rich", or is running rich the only symptom? Open headers at idle can have an effect on the O2s. The best thing to do in your situation is to do some data-logging and see what's going on with the PCM.

 

sounds like it may need a tune

does it have any codes stored, you will need to get it scanned to find out

does it have stock injectors

 

Open collectors, with the O2 sensors in the collectors, will totally screw up the A/F control.

 

pcm is untuned. i know its running rich bc i can smell the fuel in the exhaust. i took it for a small drive and it has very little power.

 

This. Close up the exhaust and it should stable out some.

 

the O2's are prolly trahsed now especially if you drove it for any distance

 

You can't expect it to run right untuned with open headers. These are basic things.

 

Well Columbus took a chance- look where it landed him..

At the VERY least put some additional exhaust on it and make a call to PCMforLess and see what he recommends. That pesky computer has a few things that need to be in order for it to run correctly.

 

LOL.....