OBD-II code · Powertrain (generic)
P0136 O2 Sensor Circuit Malfunction (Bank 1, Sensor 2)
A general fault has been detected in the downstream (post-catalyst) oxygen sensor on bank 1. The downstream sensor monitors catalyst efficiency rather than fuel mixture; with no signal, the catalyst monitor cannot run.
Is it safe to drive with P0136?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyDownstream sensor aged
- PossibleWiring chafed against exhaust
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor Downstream, Oxygen Sensor Wiring
Related codes
- P0130O2 Sensor Circuit Malfunction (Bank 1, Sensor 1)
- P0150O2 Sensor Circuit Malfunction (Bank 2, Sensor 1)
- P0156O2 Sensor Circuit Malfunction (Bank 2, Sensor 2)
- P0133O2 Sensor Slow Response (Bank 1, Sensor 1)
- P0134O2 Sensor Circuit No Activity / Slow Response (Bank 1 Sensor 1)
- P0135O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
- P0137O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)
- P0138O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)
- P0139O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.