P0158 code meaning
O2 Sensor Circuit High Voltage Bank 2 Sensor 2
Powertrain system Generic code P01xx codes Check engine light
What P0158 means
The oxygen sensor after the catalytic converter on bank 2 (sensor 2) is a switching sensor (about 0.1–0.9 V) used for converter monitoring and fine mixture trim. Bank 2 exists only on V and boxer engines with a separate downstream sensor per bank. P0158 means the signal stays above the upper limit, the bank 2 counterpart of P0138. A zirconia sensor can hardly produce more than about 1 V, so readings above 1.05–1.15 V point to an outside voltage such as the heater supply on the signal wire; GM also sees an open circuit here because of its bias voltage. Ford: above 1.1 V for 10 s; GM: above 1050 mV. From 2020 Ford also uses a 1.9 V limit depending on the feedback circuit. Monitored continuously, two trips. When it fails, the control module stops the downstream trim and cannot evaluate the converter; there is no limp mode.
P0158 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0158
- Check engine light on (usually after two drive cycles)
- Catalyst monitor readiness not set
- Usually no noticeable change in driving
Common causes of P0158
- Most likelySignal wire shorted to heater supply or battery voltage
- PossibleSensor faulty internally (heater-to-signal short)
- PossibleSignal circuit open or high-resistance (GM bias logic)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank2 sensor2Oxygen sensor wiringCatalytic converter
What each part of P0158 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 58 | The exact fault in that area. |
What to do next
- Note P0158 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0158
What does P0158 mean?
P0158 means "O2 Sensor Circuit High Voltage Bank 2 Sensor 2". The oxygen sensor after the catalytic converter on bank 2 (sensor 2) is a switching sensor (about 0.1–0.9 V) used for converter monitoring and fine mixture trim. It is a generic code, so it means the same on every make.
Is it safe to drive with P0158?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0158 fail an emissions test?
Yes, it can. P0158 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0158 to fix?
Difficulty: easy. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0158 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.