The engine P0423 Code lets you know the problem of the car engine and the powertrain problem of the engine is easy to solve. The automobile meaning of the engine code is not useful for solving the car engine and the automobile meaning of the engine code is P for OBD-II Diagnostic Powertrain (P) Trouble Code For Engine. 0 for Intake Valve Control Solenoid Circuit Low. 4 for Engine Oil Temperature Sensor Malfunction. 2 for Cylinder 10 Contribution/balance Fault and 3 for Exhaust Gas Recirculation Sensor B Circuit High. When the car engine is fixed, you can drive the car for a test drive.