FIELD GUIDETHE CODE LIBRARY

OBD-II code library

Enter the exact code from your reader or browse the fault guides below. Keep the scan report if it includes the module and code status.

TRYP0420 P0300 P0171 P0455

01BROWSE BY FAMILY

Find a code guide.

P0420Catalyst efficiency below threshold, bank 1Catalyst
P0430Catalyst efficiency below threshold, bank 2Catalyst
P0300Random or multiple cylinder misfireMisfire
P0301Cylinder 1 misfire detectedMisfire
P0171Fuel system too lean, bank 1Fuel & air
P0174Fuel system too lean, bank 2Fuel & air
P0455Large evaporative emissions system leakEVAP
P0442Small evaporative emissions system leakEVAP
P0456Very small evaporative emissions system leakEVAP
P0128Coolant below thermostat regulating temperatureCooling
P0700Transmission control system requested the warning lightTransmission
P0101Mass or volume airflow signal out of expected rangeFuel & air
U0100Lost communication with ECM or PCMNetwork
P2096Post-catalyst fuel trim system too lean, bank 1Fuel & air
P2097Post-catalyst fuel trim system too rich, bank 1Fuel & air

Some modules return enhanced or manufacturer-specific codes. Keep the full scan text and look it up with the vehicle’s year, make, model, engine and reporting module.

Read the code format