OBD2 Fault Code Library

Free lookup for thousands of OBD2 trouble codes: filter by family, read short meanings, and open deeper articles. Desktop ELM327 scanner with live data and AI guidance.

OBD2 symptoms

Look up diagnostic trouble codes by what the car is doing: misfire, overheating, rough idle, a check engine light, and other common symptoms.

P013C — O2 Sensor Slow Response - Rich to Lean (Bank 2 Sensor 2) (P013C): a powertrain (engine/transmission) fault affecting the oxygen sensor circuit. The car is usually drivable while you plan the repair. Most often caused by exhaust leak near the sensor, damaged sensor wiring or connector, oil or coolant contamination of the sensor tip.
P013D — OBD2 code P013D flags a problem with the oxygen sensor circuit (O2 sensor slow response - lean to rich (bank 2 sensor 2)). The car is usually drivable while you plan the repair. Common culprits: aged or contaminated oxygen sensor, damaged sensor wiring or connector, oil or coolant contamination of the sensor tip.
P013E — O2 Sensor Delayed Response - Rich to Lean (Bank 1 Sensor 2) (P013E): a powertrain (engine/transmission) fault affecting the oxygen sensor circuit. The car is usually drivable while you plan the repair. Most often caused by aged or contaminated oxygen sensor, blown sensor heater fuse, oil or coolant contamination of the sensor tip.
P013F — P013F — O2 Sensor Delayed Response - Lean to Rich (Bank 1 Sensor 2). A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: oil or coolant contamination of the sensor tip, blown sensor heater fuse, ECM signal circuit fault.
P0140 — OBD2 code P0140 flags a problem with the sensor and actuator circuits (02 sensor circuit no activity detected (bank 1 sensor 2)). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, blown fuse feeding the circuit, poor ground connection.
P0141 — OBD2 code P0141 flags a problem with the sensor and actuator circuits (02 sensor heater circuit malfunction (bank 1 sensor 2)). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, open or shorted wiring in the circuit, corroded, loose or damaged connector.
P0142 — 02 Sensor Circuit Malfunction (Bank 1 Sensor 3) (P0142): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by blown fuse feeding the circuit, corroded, loose or damaged connector, open or shorted wiring in the circuit.
P0143 — P0143 — 02 Sensor Circuit Low Voltage (Bank 1 Sensor 3). A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit, blown fuse feeding the circuit.
P0144 — P0144 — 02 Sensor Circuit High Voltage (Bank 1 Sensor 3). A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, blown fuse feeding the circuit, poor ground connection.
P0145 — OBD2 code P0145 flags a problem with the sensor and actuator circuits (02 sensor circuit slow response (bank 1 sensor 3)). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, control module driver fault, faulty sensor or actuator of the affected circuit.
P0146 — 02 Sensor Circuit No Activity Detected (Bank 1 Sensor 3) (P0146): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by poor ground connection, corroded, loose or damaged connector, control module driver fault.
P0147 — P0147 — 02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 3). A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: corroded, loose or damaged connector, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.
P0148 — Fuel Delivery Error (P0148): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, open or shorted wiring in the circuit, poor ground connection.
P0149 — Fuel Timing Error (P0149): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by faulty sensor or actuator of the affected circuit, poor ground connection, open or shorted wiring in the circuit.
P014A — O2 Sensor Delayed Response - Rich to Lean (Bank 2 Sensor 2) (P014A): a powertrain (engine/transmission) fault affecting the oxygen sensor circuit. The car is usually drivable while you plan the repair. Most often caused by oil or coolant contamination of the sensor tip, blown sensor heater fuse, aged or contaminated oxygen sensor.
P014B — P014B — O2 Sensor Delayed Response - Lean to Rich (Bank 2 Sensor 2). A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: aged or contaminated oxygen sensor, blown sensor heater fuse, oil or coolant contamination of the sensor tip.
P014C — OBD2 code P014C flags a problem with the oxygen sensor circuit (O2 sensor slow response - rich to lean (bank 1 sensor 1)). The car is usually drivable while you plan the repair. Common culprits: blown sensor heater fuse, damaged sensor wiring or connector, ECM signal circuit fault.
P014D — O2 Sensor Slow Response - Lean to Rich (Bank 1 Sensor 1) (P014D): a powertrain (engine/transmission) fault affecting the oxygen sensor circuit. The car is usually drivable while you plan the repair. Most often caused by exhaust leak near the sensor, damaged sensor wiring or connector, blown sensor heater fuse.
P014E — P014E — O2 Sensor Slow Response - Rich to Lean (Bank 2 Sensor 1). A fault in the oxygen sensor circuit. The car is usually drivable while you plan the repair. Typical causes: damaged sensor wiring or connector, exhaust leak near the sensor, oil or coolant contamination of the sensor tip.
P014F — OBD2 code P014F flags a problem with the oxygen sensor circuit (O2 sensor slow response - lean to rich (bank 2 sensor 1)). The car is usually drivable while you plan the repair. Common culprits: ECM signal circuit fault, aged or contaminated oxygen sensor, damaged sensor wiring or connector.
P0150 — P0150 — 02 Sensor Circuit Malfunction (Bank 2 Sensor 1). A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, blown fuse feeding the circuit, poor ground connection.
P0151 — 02 Sensor Circuit Low Voltage (Bank 2 Sensor 1) (P0151): a powertrain (engine/transmission) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by control module driver fault, corroded, loose or damaged connector, open or shorted wiring in the circuit.
P0152 — P0152 — 02 Sensor Circuit High Voltage (Bank 2 Sensor 1). A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, poor ground connection, corroded, loose or damaged connector.
P0153 — P0153 — 02 Sensor Circuit Slow Response (Bank 2 Sensor 1). A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector, control module driver fault.