Had my headgasket replaced. I replaced engine harness last year. Mechanic said the EA wire bundle was crunchy and that it suffered the same problem as the engine harness (the dealer had previously sliced into it without my permission and didn't seal it back up, either, bare wires in there). Other than leaking, it appeared to be running just fine although I had check engine light on.

Once back together it didn't run well, lopey idle and rough running.

Codes showed bad EA and Air Flow meter. I changed the air flow and that helped tremendously. Frankly, it ran as good as before -- seemed perfect to me. But...EA still showed fault.

I found a salvage one on ebay from a 96 wrecked with only 50k miles. Got it cheap. Looked great, wires seemed to be in good shape.

Well, it is faulting, too.

So, here is my question: If the car seems to run fine, good as ever, and gas mileage is good as ever -- what exactly is causing the EA to fault and until/unless the EA worsens why should I even worry about it?

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1994 C280, dark green metallic
105k miles

1991 190E 2.6, Black
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(sold to another forum member)

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