check engine light code PO121

Hello, The throttle position sensor is typically replaced as an assembly with the throttle body on your vehicle. After testing, if the throttle position sensor has failed, replacement of the throttle body assembly is quick and easy. If you follow the tube from the air filter to the engine, the throttle body is what the tube connects to on the engine, and the sensor is the black plastic piece attached to the side of the throttle body.