What it means
O2 Sensor Out of Range During Deceleration Bank 2 Sensor 2: the control module has detected this fault condition. (Code P2379)
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Bank 2 sensor 2 is the oxygen sensor downstream of the catalytic converter on the engine's second bank. During deceleration, the control module expects its exhaust-oxygen signal to move within a defined range; P2379 sets when that downstream Bank 2 signal falls outside the expected range.
Common causes
Most likely first.
- Sensor element slow or aged
- Exhaust leak between catalyst and sensor
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
How to diagnose it
- Check freeze-frame data and live oxygen-sensor readings during deceleration, comparing Bank 2 sensor 2 with the other available sensor readings.
- Inspect the exhaust between the catalytic converter and Bank 2 sensor 2 for leaks that could introduce outside air.
- Check the Bank 2 sensor 2 connector and wiring for heat damage, corrosion, or loose terminals.
- Observe whether Bank 2 sensor 2 responds during the manufacturer's specified sensor test, accounting for its downstream position.
- If the exhaust and wiring are sound, test the sensor and its heater circuit to the manufacturer's specification.
Common fixes
- Repair an exhaust leak near or upstream of Bank 2 sensor 2.
- Repair heat-damaged wiring or a poor connector at Bank 2 sensor 2.
- Replace Bank 2 sensor 2 if it responds slowly or fails the manufacturer's test.
- Recheck emissions-system operation after repair and address any separately confirmed catalyst fault.
Can I keep driving?
You can usually make a short, gentle trip if the engine runs normally, but avoid prolonged driving because emissions may rise and fuel use may increase. Stop if the check-engine light flashes or the engine begins running roughly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.