P0152O2 Sensor Circuit High Voltage (bank 2 sensor 1)
What it means
The oxygen sensor bank 2 sensor 1 stays at a high voltage (rich reading) or above the possible range. The upstream sensor (before the catalyst) is what the ECU uses to correct the mixture.
Symptoms
- Check engine light
- Higher fuel consumption
- Possibly a rough idle or failed emissions test
Common causes
- Real rich condition (leaking injector, high fuel pressure, purge valve stuck open)
- Signal wire shorted to the heater supply or to voltage
- Contaminated sensor (coolant, oil or silicone)
- Failed sensor
What to check first
- Check fuel trims and fuel pressure
- Create a vacuum leak: a good sensor drops below 0.2 V
- Check the signal wire for a short to the heater circuit
Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.