[spcmafia]

Originally Posted by Dzmitry

Well the O2 is usually a good check, but more times than not (at least from my personal experience), a fairly beat catalytic converter is the real culprit - in which case the O2 picks up readings that aren't standard and you get the code. So see first if the O2 fixes it and then go from there.

EDIT: Just noticed you mentioned he has un-catted headers.

I believe he's running catless headers. But we'll see.