OBD-II code · Powertrain (generic)
P0158 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
The ECU detects abnormally low voltage from the downstream O2 sensor on bank 2 (alternate definition mapping in some manufacturers' interpretation). Indicates persistent lean reading, open sensor or wiring shorted to ground.
Is it safe to drive with P0158?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyLean condition on bank 2
- PossibleO2 sensor failed
- 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
- 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 B2s2, Oxygen Sensor Wiring
Related codes
- P0144O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)
- P0157O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
- P0164O2 Sensor Circuit Low Voltage (Bank 2 Sensor 3)
- P0155O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 1)
- P0156O2 Sensor Circuit Malfunction (Bank 2, Sensor 2)
- P0159O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)
- P015AO2 Sensor Delayed Response - Rich to Lean Bank 1 Sensor 1
- P015BO2 Sensor Delayed Response - Lean to Rich Bank 1 Sensor 1
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.