Hearing a knock around 2,500 rpm under a light load

2008 PONTIAC G5

80,000 MILES • 2.2L • 4 CYL • 2WD • MANUAL

LAWRENCE LUBASH

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Goes away after a few hundred more rpm's. Does not knock under heavy load. I feel no vibration. There is no loss of power. The only code it throws is a P0411 Secondary air valve stuck. Any possible causes?

Sep 18, 2019 at 9:00 AM

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SCGRANTURISMO

AUTOMOTIVE REPAIR CONTRIBUTOR
4,897 POSTS

Hello,

In the diagrams down below I have included the vehicle manufacturers diagnostic troubleshooting guide for DTC P0411 for your vehicle. Please go through this guide and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

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Sep 18, 2019 at 3:03 PM