The engine P0402 Code is found when the car engine is verified and tested. Do not allow wrong meaning of the code for solving the car engine. The engine code has a right and wrong meaning. For solving the car engine, you should depend on the real meaning of the engine code. However, meaning of the engine code is found from online also but that is not perfect for the car engine always. You should study the real meaning of the car engine code. You must allow right meaning of the code and that meaning is from the car manufacturer of the car.