What RPM does it idle at? I thought there was a re-flash to fix low idle? Maybe I'm wrong.
If the COP is misfiring, wouldnt there be a check engine light? I'm curious because my pops 04 has what feels like a misfire at highway speeds under load and he thinks its tranny but I think it just needs plugs and COP changed. Thing is, his doesnt have a CEL either. No codes stored in the system either.