1997 3.1 Lumina ECM?

Mine started running rough intermittently and progressively got worse. I've checked and/or replaced most every thing MAP, MAF, EGR, TPS etc... This weekend the fuel injectors. Now it's throwing a P1200 trouble code.

I'm wondering if its the ECM? can these be checked??

The code refers to the fuel injection control circuit. This could mean your fuel injectors are going bad, so that's one thing to look into. The part that makes this difficult is the fact that luminas from that final generation were often electrical basket cases. So other causes could be the wiring harness getting all f*cked up resulting in short circuits and other things of that nature, so you may want to check the wiring harness. You asked about the ECM... there's a distinct possibility that there's a problem with that as well.

Thanks for the replies. I guess I'll just dig in!!!