The engine P0303 Code is found in the car engines only and you will get several meanings of the same engine code. Due to use of the wrong meaning of the code, you may get serious problem in the car engine. Once the car engine has a problem, you should not drive the car with the engine problem. Do not try to solve the car engine problem by yourself if you are unable to fix the car engine. You must not give the car to immature automobile engineer for solving the car engine. Do not apply untrusted meaning of the code.