OBD2 Code Lookup
Plain-English answers for every check engine code. Search 568 diagnostic trouble codes with plain-English causes, fixes, and costs.
Most common codes
P0420
Catalyst System Efficiency Below Threshold (Bank 1)
P0171System Too Lean (Bank 1)
P0300Random/Multiple Cylinder Misfire Detected
P0301Cylinder 1 Misfire Detected
P0128Coolant Thermostat (Coolant Temperature Below Regulating Temperature)
P0442Evaporative Emission Control System Leak Detected (Small Leak)
P0455Evaporative Emission Control System Leak Detected (Large Leak)
P0101Mass or Volume Air Flow (MAF) Sensor Circuit Range/Performance
P0174System Too Lean (Bank 2)
P0430Catalyst System Efficiency Below Threshold (Bank 2)
P0302Cylinder 2 Misfire Detected
P0303Cylinder 3 Misfire Detected
P0304Cylinder 4 Misfire Detected
P0421Warm Up Catalyst Efficiency Below Threshold (Bank 1)
P0456Evaporative Emission System Leak Detected (Very Small Leak)
P0401Exhaust Gas Recirculation (EGR) Flow Insufficient Detected
P0740Torque Converter Clutch Circuit Malfunction
P0700Transmission Control System Malfunction
P0562System Voltage Low
P0340Camshaft Position Sensor Circuit Malfunction