OBD-II code · Powertrain (generic)
P0151 O2 Sensor Circuit Low Voltage (Bank 2, Sensor 1)
Same condition as P0131 but on bank 2. The upstream sensor sees a continuously lean exhaust on bank 2 or has a signal short to ground.
Is it safe to drive with P0151?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyExhaust leak upstream of the sensor
- PossibleBank 2 running lean (vacuum leak, fuel pressure)
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor Upstream, Exhaust Pipe Pre Cat
Related codes
- P0131O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)
- P0137O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)
- P014EO2 Sensor Slow Response - Rich to Lean Bank 2 Sensor 1
- P014FO2 Sensor Slow Response - Lean to Rich Bank 2 Sensor 1
- P0150O2 Sensor Circuit Malfunction (Bank 2, Sensor 1)
- P0152O2 Sensor Circuit High Voltage (Bank 2, Sensor 1)
- P0153O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
- P0154O2 Sensor Circuit No Activity / Slow Response (Bank 2 Sensor 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.