OBD-II code guide
P0136 Oxygen Sensor Circuit Bank 1 Sensor 2
P0136 means the downstream oxygen sensor circuit on bank 1 is not behaving as expected.
What it means
The catalyst monitoring sensor signal may be unreliable.
Common symptoms
- Check engine light
- Usually no drivability symptom
- Failed emissions test
- Possible catalyst monitor issue
- Possible P0420
Likely causes
- Downstream oxygen sensor fault
- Wiring damage
- Exhaust leak
- Connector issue
- Catalyst monitoring problem
First checks
- Inspect downstream sensor wiring.
- Check for exhaust leaks.
- Review catalyst and oxygen sensor data.
- Do not assume this alone means the converter is bad.