Bad 'Smog Air Pump' ?
Ok, I got a 'service engine soon' light the same day wifey comes home saying there is a "new rattle" on the Yukon.
The rattle sounds like a loose exhaust heat shield, or even gravel caught above and vibrating on a heat shield, but it resonates throughout the entire length of the exhaust system. My best guesstimate was that it appeared to be originating from inside the right (pass.) side catalytic converter. Had the local AutoZone read the code which said Cat Failure due to 1.) vacuum leak, or; 2.) engine oil leak into Cat, or; 3.) O2 sensor failure. I tend to rule out 2 and 3 because of the rattle, and not sure if item 1 would even cause a rattle, so I was leaning towards broken honeycomb inside the cat itself maybe?
A call to the service dept. this a.m. brought up another possibility - a bad emissions system 'Smog Air Pump'. What's that, and is it easily servicable? Doesn't look too expensive.
ACDELCO PT1116 [AIR PUMP] CONNECTOR,MOT-SECD AIR INJN PUMP OEM#12085212 $13.63
ACDELCO PT374 [AIR PUMP] CONNECTOR,SOL-SECD AIR INJN BYPASS VLV OEM#12102747 $16.20
Anybody got a clue?
2004 | 6MTs | Diamond Graphite/Graphite
Upstate NY
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