The automobile dictionary meaning of the engine P0420 Code. The automobile dictionary meaning is found easily and you can easily find the automobile dictionary meaning easily. The automobile dictionary 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 Crankshaft Position Sensor A Circuit Malfunction and 0 for Exhaust Gas Recirculation Sensor B Circuit High. Find the real cause of the car engine problem and check all symptoms of the car engine for solving the car engine. When the car engine is ok, a test drive recommended.