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.
Car Problem Reports
Chevrolet Silverado 1500 Check Engine Light Due to Restricted Secondary Air Injection Check Valves
Chevrolet Silverado 1500 Problem
Exhaust & Emissions Affected: Gasoline
Average Mileage: 96,766 mi (26,000 mi - 170,000 mi)
Visitor, 2004 Chevrolet Silverado 1500
check engine light - digital trouble code P0449 says a malfunction of vent solonoid valve and my on board dash says i have a loose gas cap - has this been a common problem? this vehicle has 56,000 miles
Visitor, 2006 Chevrolet Silverado 1500, 26,000 mi
engine light comes one, I take it to the dealer and they don't know what's wrong. they shut it off and a few days later it come on. I don't take my truck to the dealership.
Visitor, 2001 Chevrolet Silverado 1500, 94,000 mi
P1416 DTC code "Check engine light on"