P0160O2 Sensor Circuit No Activity Detected (bank 2 sensor 2)
What it means
The oxygen sensor bank 2 sensor 2 signal stays flat (around 0.45 V) once the engine is warm. The ECU sees no switching at all. The downstream sensor (after the catalyst) is mainly used to check how well the catalyst works.
Symptoms
- Check engine light
- Usually no change in how the car drives
- Catalyst monitor may not complete
Common causes
- Open signal circuit
- Sensor heater not working, so the sensor never gets hot enough
- Failed sensor
- Engine never reaching closed loop (e.g. thermostat stuck open)
What to check first
- Check the heater circuit and its fuse
- Graph the sensor once warm; a flat 0.45 V usually means open circuit
- Check that coolant temperature reaches normal
Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.