Agree, for sure. When you see mutiple codes pop up in a single moment, that can be a clue as to what causes that unique pattern....






Unless one failed at 100k, one at 120k and one at 150k. for example. For all we know the CEL has been on for years, only once it starts driving like crap does this become urgent. Hypothetical of course, not speaking to OPs facts







The heater circuit error cannot be explained by injectors...maf...fuel...pressure sensors..blah blah blah. Only one thing causes that code: an open circuit (ie no current) in the circuit that connects to the O2 sensor preheater. The list is short: O2 sensor, wire(s), connector, fuse. (Or...the DME is faulty, just to be accurate.)



You ask 'any work done?'... indeed, someone messing with cats and O2s, might do that.


Has anyone asked:



"How long has the CEL been on?"


"Did ALL these codes appear at the same time, just all at once and recently?


"If not, how did these CELs evolve over time?