Rough idling strong, exhaust smells like rotten eggs

2005 GMC YUKON
153,000 MILES • 5.3L • V8 • 2WD • AUTOMATIC
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SLEE1978
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Rough idling strong exhaust smell check engine light pulled codes and got the following: P0455, P0171, P0300, P0131 and P0102. Exhaust smells like rotten eggs. Unplugged MAF sensor while truck running and nothing happens is this normal? Please help.
Dec 31, 2018 at 2:47 PM
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ASEMASTER6371
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Good evening,

The smell comes from the catalytic converter. when the engine as a misfire, too much fuel gets into the catalytic converter and the small is the result.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

I would start with a fuel pressure test. that is a common failure for the 300 code.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

The 102 is you disconnecting the mass air flow with it running. by the way, that is not a test of anything. it just puts the engine in default fuel mapping mode.

The 455 is an EVAP code. attached is the location of the vent valve.

The 131 may be related to the misfire and should go away once the engine runs smooth again.

Roy
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Dec 31, 2018 at 3:05 PM