Many parts of the car engine may faulty and you need to test the car engine. The car engine P1904 Code is found online and this engine code lets you know about the problem. The problem is powertrain. The important things is accelerator Pedal Position Sensor 1 Circuit Low and the engine P2127 – Accelerator Pedal Position Sensor 2 Circuit Low would lead you to dubious a defective accelerator pedal position sensor. If you do not know how to fix the car engine and you do not have all things for solving the car engine, you must not try to fix the car engine.