Set a check engine light with a momentary "bucking" and misfiring of the engine which cleared itself up after just a few seconds--- Pulled the code at AutoZone, came back (dammit, didn't write the exact code down) "Catalyst efficiency below threshold"--- Suggested order of troubleshooting? Had a Dodge mechanic suggest to me the downstream O2 sensor---could that be it exactly?
TIA
Well, when this happened on my vehicle, it actually was the catalytic converter. Everyone told me that it wasn't, or wouldn't be. I even did the temperature test to see if the outflow was hotter than the inflow, which proved to be somewhat inconclusive. No obvious damage to the cat either...I cut the old one in two afterwards also, to see if it was clogged (and it wasn't). Anyhow, put a new cat on, and code hasn't tripped again.
Of course, I'd try and eliminate other items first, as the cat is pretty expensive.
Paul
So, Fred 2, do you think that the converter is faulty, or the sensor? I would like to rid myself of the check engine light, if possible. You're right, drivability does not seem to be affected.
Is there an impedance check for the sensor?
TIA
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