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 Cadillac Escalade
5 people reported this problem
0 people shared problem details
Illumination of the Check Engine Light can be caused by a loose or worn gas cap.
Check engine light comes on when the gas tank is below 1/2. Replaced gas cap and that seemed t...
I also added a new K&R Intake system. I get Engine Light Codes PO101- Mass/Volume Air Flow Circ...