IS it possible for the prom to go bad in an ECM. When I got my car the ECM was dead, I believe. I replaced the ECM and put the chip from the dead ecm in? Haven't been able to get rid of rich condition on cc quadrajet, wondering if this could be caused by bad prom.

 

I may be speaking from my **** on this, but AFAIK a PROM can go bad; the ECM is conceptually the same as any other computer system. The PROM is the brain - it contains most (or all) of the instructions - and it can go bad just as any other electronics component can go bad.

If you replaced the ECM and used your existing PROM, three things SEEM to be possible:

a) your new ECM is bad
b) your PROM is bad
c) both are bad

I'm not mechanically-inclined enough to address your other problems, unfortunately. Hope this helps.

Ray