Oxygen Sensor Diagnostic Codes
Oxygen sensors are critical for fuel efficiency and emissions. Here's how to diagnose and fix O2 sensor problems.
Oxygen Sensor Circuit Malfunction Bank 1 Sensor 1
The upstream oxygen sensor on bank 1 is not functioning properly. This sensor is critical for fuel mixture control.
Oxygen Sensor Circuit Low Voltage Bank 1 Sensor 1
The upstream oxygen sensor on bank 1 is reading consistently low voltage, indicating a lean condition or sensor failure.
Oxygen Sensor Circuit High Voltage Bank 1 Sensor 1
The upstream oxygen sensor on bank 1 is reading consistently high voltage, indicating a rich condition or sensor failure.
Oxygen Sensor Circuit Slow Response Bank 1 Sensor 1
The upstream oxygen sensor on bank 1 is responding too slowly to changes in exhaust oxygen content.
Oxygen Sensor Circuit No Activity Detected Bank 1 Sensor 1
The upstream oxygen sensor on bank 1 shows no activity or switching between rich and lean conditions.
Oxygen Sensor Heater Circuit Malfunction Bank 1 Sensor 1
The heater circuit for the upstream oxygen sensor on bank 1 is not working properly.
Oxygen Sensor Circuit Malfunction Bank 1 Sensor 2
The downstream oxygen sensor on bank 1 (after catalytic converter) is not functioning properly.
Oxygen Sensor Circuit Low Voltage Bank 1 Sensor 2
The downstream oxygen sensor on bank 1 is reading consistently low voltage.
Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2
The downstream oxygen sensor on bank 1 is reading consistently high voltage.
Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2
The downstream oxygen sensor on bank 1 is responding too slowly to exhaust changes.
Oxygen Sensor Circuit No Activity Bank 1 Sensor 2
The downstream oxygen sensor on bank 1 shows no switching activity.
Oxygen Sensor Heater Circuit Malfunction Bank 1 Sensor 2
The heater circuit for the downstream oxygen sensor on bank 1 is not working.
Fuel and Air Metering Code P0142
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0143
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0144
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0145
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0146
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0147
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0148
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0149
Diagnostic trouble code related to fuel delivery and air intake system performance.
Oxygen Sensor Circuit Malfunction Bank 2 Sensor 1
The upstream oxygen sensor on bank 2 is not functioning properly. This applies to V6/V8 engines.
Oxygen Sensor Circuit Low Voltage Bank 2 Sensor 1
The upstream oxygen sensor on bank 2 is reading consistently low voltage.
Oxygen Sensor Circuit High Voltage Bank 2 Sensor 1
The upstream oxygen sensor on bank 2 is reading consistently high voltage.
Oxygen Sensor Circuit Slow Response Bank 2 Sensor 1
The upstream oxygen sensor on bank 2 is responding too slowly to exhaust changes.
Oxygen Sensor Circuit No Activity Bank 2 Sensor 1
The upstream oxygen sensor on bank 2 shows no switching activity.
Oxygen Sensor Heater Circuit Malfunction Bank 2 Sensor 1
The heater circuit for the upstream oxygen sensor on bank 2 is not working.
Fuel and Air Metering Code P0156
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0157
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0158
Diagnostic trouble code related to fuel delivery and air intake system performance.
Fuel and Air Metering Code P0159
Diagnostic trouble code related to fuel delivery and air intake system performance.