Q: Check Engine Light is on - 2009 Chevrolet Malibu

If you have codes to a sensor, it does not always mean the sensor is bad. There may be wiring or connector problems causing erratic or incorrect sensor input to the computer. The code stored in a computer is only a tool for a mechanic to diagnose the problem following the pinpoint tests for the code received.

After repairs, the code needs to be cleared and whether the problem has been fixed should be verified. The vehicle may have wire connection corrosion causing a loose connection at the engine control module. You may need to disconnect it, add dielectric lube to connection pins, reconnect it, and then clear the codes.

I recommend having a certified mechanic, such as one from YourMechanic, determine why the Check Engine Light is on and suggest any needed repairs.