P0136: O2 Sensor Circuit (Bank 1 Sensor 2)

What does P0136 mean?

There's a circuit problem with the bank 1, sensor 2 oxygen sensor. Sensor 2 is the downstream sensor, mounted after the catalytic converter; it mainly watches how well the converter is working and has little effect on fuel mixture. Because of that, this code rarely changes how the car drives, but it can keep the computer from running the catalyst test.

Generic OBD-II definition: O2 Sensor Circuit (Bank 1 Sensor 2). Confirm applicability in your vehicle service information.

Common causes

• Downstream sensor failed
• Wiring damaged by road debris or heat under the car
• Connector corroded from water and road salt
• Exhaust leak near the converter

Symptoms

• Check engine light only, in most cases
• Catalyst readiness monitor may not complete, which can fail an inspection

Can I keep driving with P0136?

Severity: Low Usually safe to keep driving, but get it checked.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Inspect the wiring and connector underneath the car
• Watch the sensor on a scanner; a healthy downstream sensor reads fairly steady, often around 0.45 to 0.7 volts
• Replace the sensor if the circuit tests good