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
P0456Evaporative Emission System Leak Detected (Very Small Leak)
P0430Catalyst System Efficiency Below Threshold (Bank 2)
P0128Coolant Thermostat (Coolant Temperature Below Regulating Temperature)
P0455Evaporative Emission Control System Leak Detected (Large Leak)
P0174System Too Lean (Bank 2)
P0442Evaporative Emission Control System Leak Detected (Small Leak)
P0113Intake Air Temperature (IAT) Sensor Circuit High Input
P0301Cylinder 1 Misfire Detected
P0302Cylinder 2 Misfire Detected
P0011"A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
P0016Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)
P0101Mass or Volume Air Flow (MAF) Sensor Circuit Range/Performance
P0172System Too Rich (Bank 1)
P0303Cylinder 3 Misfire Detected
P0304Cylinder 4 Misfire Detected
P0441Evaporative Emission Control System Incorrect Purge Flow
P0446Evaporative Emission Control System Vent Control Circuit Malfunction