One or both secondary air injection check valves may become restricted causing poor air flow resulting in illumination of the Check Engine Light. It is often recommend to replace both check valves even if a fault code is set for only one bank of cylinders. Replacing only one valve may result in a return trip to the repair shop.
Check Engine Light Due to Restricted Secondary Air Injection Check Valve on Chevrolet Avalanche 1500
Average mileage: 78,000 (78,000–78,000)
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2002 Chevrolet Avalanche 150078,000Visitor
Check engine light is on, checked gas cap it was tight, not repaired yet
Notice of "check Gas cap" came up dashboard Tuesday. Gas cap was tight. Repair shop Cleared cod...
were are the secondary air injection check valves
so far nothing has happened ...i was told that it was to due with the sealed fuel system ??......