I read your post and the responses and you'd mentioned that.

However, driving fine might or might not mean anything vis a vis a CEL. It might be the silly small evap leak code (often just a loose gas cap) or it might be a MAF or O2 sensor (or a hundred other things). I mentioned those specifically because while they may or may not cause driveability issues, the compensations they trigger in the engine management system can, for example, over time build up combustion chamber deposits and cause the cats to fail.

Also, driving around with a CEL on is never a wise choice, and that this owner did so suggests a lack of concern about the car at all, meaning there are potentially LOTS of things that have been neglected in addition to the ones that are snarling and snapping at present.