Car has intermittent rough idle....runs great at faster speeds. Took it to our local Chevy dealer they diagnosed it as a "faulty ECM" and wanted over $500 to fix it. I can order a rebuilt ECM for slightly over $100.
Temped to try this but a few questions first:
1. Where exactly is the ECM?
2. The part indicates "The PROM[s]/CALPACK must be transferred from the original module to the replacement module." it looks like it just plugs into the replacement - correct?
3. Is there any reprogramming needed once replaced?
Thanks in advance for your help.