P0152 O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
The upstream (before the catalytic converter) oxygen sensor, Bank 2 Sensor 1, stays at high voltage, which reads as rich.
Common causes
- Rich running from leaking injector or high fuel pressure
- Faulty sensor
- Signal shorted to voltage
Symptoms
- Check engine light
- Fuel smell from exhaust
What to check
- Check fuel trims and fuel pressure
- Inspect wiring
- Replace sensor if contaminated
Manufacturers may add their own detail to generic codes. If your vehicle shows a different description for P0152, follow the service information for that make and model.