2007 Hummer H2 missfire cyl 2 4 6 8

2007 HUMMER H2
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HEMI FRANK
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Engine Performance problem
2007 Hummer H2 V8 Four Wheel Drive Automatic 73k miles

low compresson 2 4 6 8 30 psi 1 3 5 7 125psi ck injectors ok new spark plug no oil fouling
Dec 8, 2009 at 5:32 PM
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FACTORYJACK
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Try removing the pre-cat O2 sensor on bank 2, or the bank with 2 4 6 and 8 on it. Check a cylinder and see if your compression goes up. This may be remedial, but if the air can't exhaust, it is not going to pull air in. I have never checked compression when a plugged converter is suspected. I either did an exhaust backpressure test, or removed the O2 and observed if my misfiring went away.
Dec 8, 2009 at 10:31 PM
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HEMI FRANK
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hummer has had problem with pass side cats . injector leaning out 2468 cly.burning piston.will repair under warranty
Dec 23, 2009 at 5:01 PM
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