When the cylinder runs rich, unburnt fuel leaks into the exhaust, creating a backfire or popping sound. When the ECU notices the problem, it might overcompensate by changing how much fuel gets delivered to the cylinder. This defect causes an exhaust leak that affects the way the fuel is combusted. It can also fail to seal properly when closed. The exhaust valves need to open and close at precise times to ensure the right amount of pressure is always present.Ī bent exhaust valve can end up in the wrong position. If an exhaust valve is bent, it affects how the fumes leave the cylinder. The engine valves are not electronic, and therefore the trouble codes will not directly say that an engine valve is bent, but it may say something about misfires or wrong air-fuel mixture. You can check the trouble codes with an OBD2 scanner to look for any air-fuel mixture related trouble codes. If any of your engine valves are bent, it will definitely result in a check engine light. If something is wrong with any of the sensors or if any parameter is out of range, it will light up the check engine light on your dashboard. Modern cars monitor all sensors in your car engine in real-time to make sure its performance is optimal. Here is a more detailed list of the signs of bent engine valves to look for: 1. The main symptoms of bent engine valves include:

Timing cover leak symptoms