Oxygen sensor
P0136
Oxygen Sensor Circuit (Bank 1 Sensor 2)
An oxygen sensor in the exhaust is giving a reading the computer doesn't expect. The sensors before the catalytic converter steer the fuel mixture, and the ones after it watch the converter.
Fine to drive
Can I keep driving? Yes, in most cases. It won't hurt the car in the short term, but get it fixed. A check engine light that's already on can't warn you about a new problem. It drives fine, but the mixture may run rich or lean. Over months that costs fuel and can overheat the catalytic converter.
What the words mean
- Bank 1 is the side of the engine with cylinder 1. A four-cylinder engine has only one bank.
- Sensor 2 is the oxygen sensor after the catalytic converter.
Common causes
- An old, slow sensor (they wear out with age and miles)
- An exhaust leak near the sensor
- Wiring or connector damage
- A real mixture problem, such as a vacuum leak or a leaking injector, that the sensor is reporting correctly
Listed roughly from most to least likely. The same code can have different causes on different cars.
What to do
- Look for other codes first. A lean, rich or misfire code is the real story, and the sensor is only the messenger.
- Listen for an exhaust leak (a ticking that fades as the engine warms).
- Replace the sensor named in the code if it's the only code and the sensor is old.
General guidance. Your owner's manual wins. If a red warning light is on or the car drives differently, stop safely and get help.
Related codes
- P0130Oxygen Sensor Circuit (Bank 1 Sensor 1)
- P0131Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 1)
- P0132Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 1)
- P0133Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 1)
- P0134Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
- P0137Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 2)
- P0138Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2)
- P0139Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 2)
Track this automatically in Tagwell Auto
Tagwell Auto keeps your car's service dates and mileage, so when a code shows up you know what was done last. With a Bluetooth reader for the car's diagnostic port (called OBD-II), the phone app can read the code itself.