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9,253 diagnostic guides
Find codes by symptomChoose what you notice to search matching code guides.
Rough idle or shakingVibration while stoppedHard to startLong cranking or no-startEngine stallsCuts out at idle or on the roadHesitates or loses powerSlow response when acceleratingBattery light is onCharging system warningHarsh gear changesDelayed or rough shifting
A symptom can have several causes. Treat matching codes as clues and follow the diagnostic checks in each guide.
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These are generic OBD2 definitions. Exact make, model, engine, and year compatibility will appear after vehicle-fitment data is added.
Diagnostic codes
Showing 1–24 of 378
P0142Oxygen Sensor Circuit Bank 1 Sensor 3Check soonEmissions System45–120 minutes for initial diagnosisP0159Oxygen Sensor Circuit Slow Response Bank 2 Sensor 2Check soonEmissions System45–120 minutes for initial diagnosisP0407Exhaust Gas Recirculation Sensor B Circuit LowCheck soonEmissions System30–90 minutes for initial diagnosisP0408Exhaust Gas Recirculation Sensor B Circuit HighCheck soonEmissions System30–90 minutes for initial diagnosisP0409Exhaust Gas Recirculation Sensor A CircuitCheck soonEmissions System30–90 minutes for initial diagnosisP040AEGR Temperature Sensor A CircuitCheck soonEmissions System30–120 minutes for initial diagnosisP040BEGR Temperature Sensor A Circuit Range/PerformanceCheck soonEmissions System30–120 minutes for initial diagnosisP040CEGR Temperature Sensor A Circuit LowCheck soonEmissions System30–120 minutes for initial diagnosisP040DEGR Temperature Sensor A Circuit HighCheck soonEmissions System30–120 minutes for initial diagnosisP040EEGR Temperature Sensor A Circuit Intermittent/ErraticCheck soonEmissions System30–120 minutes for initial diagnosisP040FEGR Temperature Sensor A/B CorrelationCheck soonEmissions System30–120 minutes for initial diagnosisP041AEGR Temperature Sensor B CircuitCheck soonEmissions System30–120 minutes for initial diagnosisP041BEGR Temperature Sensor B Circuit Range/PerformanceCheck soonEmissions System30–120 minutes for initial diagnosisP041CEGR Temperature Sensor B Circuit LowCheck soonEmissions System30–120 minutes for initial diagnosisP041DEGR Temperature Sensor B Circuit HighCheck soonEmissions System30–120 minutes for initial diagnosisP041EEGR Temperature Sensor B Circuit Intermittent/ErraticCheck soonEmissions System30–120 minutes for initial diagnosisP0424Heated Catalyst Temperature Below Threshold (Bank 1)Check soonEmissions System30–90 minutes for initial diagnosisP0425Catalyst Temperature Sensor Circuit (Bank 1, Sensor 1)Check soonEmissions System30–90 minutes for initial diagnosisP0426Catalyst Temperature Sensor Circuit Range/Performance (Bank 1, Sensor 1)Check soonEmissions System30–90 minutes for initial diagnosisP0427Catalyst Temperature Sensor Circuit Low (Bank 1, Sensor 1)Check soonEmissions System30–90 minutes for initial diagnosisP0428Catalyst Temperature Sensor Circuit High (Bank 1, Sensor 1)Check soonEmissions System30–90 minutes for initial diagnosisP0429Catalyst Heater Control Circuit (Bank 1)Check soonEmissions System30–90 minutes for initial diagnosisP042ACatalyst Temperature Sensor Circuit Bank 1 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosisP042BCatalyst Temperature Sensor Circuit Range/Performance Bank 1 Sensor 2Check soonEmissions System30–120 minutes for initial diagnosis