The automobile meaning of the P0304 Code is found online for free but is not used for the car engine solution. The real meaning of the code is necessary to use for solving the car engine. Do not use wrong meaning of the engine code. You may face new problems in the car engine. However, your car engine has a correct meaning of the code and that meaning of the code is found from the car manufacturer. That meaning is correct and using this meaning of the code, you may not face any problem in the car engine. By the test drive, the car engine is ok or not identifiable.