OBD-II trouble codes

Ranked by how often the code appears in real NHTSA owner complaints - not alphabetically. P = powertrain, B = body, C = chassis, U = network.

Browse by symptom

Rough idle / shaking Stalling Hard starting Hesitation / power loss Flashing check engine light Poor fuel economy Shifting problems Temperature / cooling ABS / dashboard lights

Codes whose typical symptoms include poor fuel economy - most serious first:

P0300Random/Multiple Cylinder Misfire Detected P0351Ignition Coil A Primary Control Circuit/Open P0011A Camshaft Position - Timing Over-Advanced or System Performance Bank 1 P0101Mass or Volume Air Flow Sensor A Circuit Range/Performance P0106Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Range/Performance P0107Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Low P0108Manifold Absolute Pressure/Barometric Pressure Sensor Circuit High P0117Engine Coolant Temperature Sensor 1 Circuit Low P0118Engine Coolant Temperature Sensor 1 Circuit High P0172System Too Rich Bank 1 P0741Torque Converter Clutch Circuit Performance/Stuck Off P0113Intake Air Temperature Sensor 1 Circuit High Bank 1 P0128Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)P0131O2 Sensor Circuit Low Voltage Bank 1 Sensor 1 P0133O2 Sensor Circuit Slow Response Bank 1 Sensor 1 P0135O2 Sensor Heater Circuit Bank 1 Sensor 1 P0155O2 Sensor Heater Circuit Bank 2 Sensor 1 P0325Knock/Combustion Vibration Sensor A Circuit P0430Catalyst System Efficiency Below Threshold Bank 2 P0442EVAP System Leak Detected (small leak)P0457EVAP System Leak Detected (fuel cap loose/off)