P0158 Oxygen sensor circuit high voltage (bank 2, sensor 2)
What P0158 means
The downstream oxygen sensor on bank 2, after the catalytic converter, is reporting a voltage that stays too high. The engine computer cannot use it to check the converter on that bank. Bank 2 is the side of a V6, V8 or boxer engine that does not contain cylinder 1.
P0158 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- Medium
- Typical repair cost
- 80–350 €
- Workshop time
- 0.3–1.5 h
- Repair difficulty
- Easy
- DIY possible
- Yes
- Check engine light
- Yes
- Affects emissions test
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine light on
- Usually no noticeable change in how the car drives
- Catalyst readiness monitor not completing
- Possible failed emissions test at inspection
Common causes
- Failing downstream oxygen sensor
- Signal wire shorted to voltage or to the heater circuit
- Sensor contaminated by oil or coolant
- Bank 2 running rich
Can I keep driving with P0158?
You can keep driving, but have it checked within one to two weeks. The engine is rarely affected, but the catalyst check cannot run and the car may fail its emissions inspection.
What to check first
- Check bank 2 fuel trims and upstream sensor to rule out rich running.
- Inspect the harness for melted or fused wires.
- Unplug the sensor and see whether the reading changes; if it stays high, the wiring is shorted.
- Replace the sensor if mixture and wiring are fine.
Related codes
- P0157 Oxygen sensor circuit low voltage (bank 2, sensor 2)
- P0156 Oxygen sensor circuit (bank 2, sensor 2)
- P0155 Oxygen sensor heater circuit (bank 2, sensor 1)
- P0153 Oxygen sensor slow response (bank 2 sensor 1)
- P0152 Oxygen sensor circuit high voltage (bank 2, sensor 1)
- P0151 Oxygen sensor circuit low voltage (bank 2, sensor 1)
- P0150 Oxygen sensor circuit (bank 2 sensor 1)
- P0160 Oxygen sensor circuit no activity detected (bank 2, sensor 2)
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
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