P0136 O2 Sensor Circuit (Bank 1, Sensor 2)
What does P0136 mean?
P0136 — O2 Sensor Circuit (Bank 1, Sensor 2) (bank 1). This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects o2 sensor circuit (bank 1, sensor 2) on bank 1. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0136
- Failed downstream oxygen sensor
- Damaged wiring or connector
- Exhaust leak near the sensor
- Catalyst fault causing abnormal readings
- Contaminated sensor
How to fix P0136
- Inspect for exhaust leaks near the downstream sensor
- Watch the downstream sensor voltage with a scan tool
- Test the sensor signal and heater circuits
- Check catalyst efficiency before blaming the sensor
- Replace the sensor or catalyst as identified