Maybe this means I need a code scanner. It predates OBD-II. Is it OBD? Would an OBD-II scanner work?
I'm not the primary driver, and this just started, but this what I've observed: The car runs great, as smooth as ever, as much power, etc.
When warm, the light comes on in slow stop & go driving. Freeway, or a little faster, and the light goes off.
Any likely suspects? O2 sensor? PVC valve? Cat?
Thanks much! David