- Idle air control valve: Helps regulate the amount of air that enters the engine at idle. If the idle air control valve is faulty or dirty, it can cause the car to run on and off.
- Fuel injector: Provides fuel to the engine's cylinders. If the fuel injector is faulty, it can cause the engine to run on after the ignition is released due to a rich air-fuel mixture.
- Throttle position sensor: Reports throttle position to the car's computer. If the sensor is faulty, the computer may not know to stop fuel flow when you let go of the gas pedal.
- Ignition switch: Turns the ignition system on and off. If the ignition switch is faulty, it may not be able to turn the ignition off fully.
- Vacuum leak: Sucks air into the engine, which can cause the car to run lean and possibly run on after the ignition is released.
If your car is running after you turn the key off, take it to a mechanic for an evaluation.
