What it means
The control module detects that the Bank 2 Sensor 2 oxygen-sensor signal remains lean or is biased lean. This code does not by itself diagnose a failed sensor or catalytic converter.
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 bank 2 exhaust. This code sets when its signal stays lean or appears lean for too long, which may reflect an exhaust leak near that sensor, a sensor fault, or a wiring problem.
Common causes
Most likely first.
- Faulty downstream oxygen sensor
- Exhaust leak near the sensor
- Signal wiring or connector fault
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
How to diagnose it
- Review freeze-frame and live data for bank 2 Sensor 2 to see whether its reading remains lean as conditions change, and check for related fuel-trim or misfire codes.
- Inspect the bank 2 exhaust joints and area around the downstream sensor for leaks that could add oxygen to the reading.
- Check bank 2 Sensor 2's connector and wiring for heat damage, corrosion, loose terminals, or contact with hot exhaust parts.
- Compare downstream activity on bank 2 with the upstream sensor and check the heater and signal circuit using the manufacturer's procedure.
- If there is no exhaust or wiring fault, test bank 2 Sensor 2 response under the manufacturer's conditions before replacing it.
Common fixes
- Repair an exhaust leak near bank 2 Sensor 2.
- Repair damaged wiring or corroded connector terminals in the bank 2 sensor circuit.
- Replace bank 2 Sensor 2 if it fails the response or circuit test.
- Correct any upstream engine problem indicated by related codes that could keep bank 2 exhaust lean.
Can I keep driving?
If the engine runs normally, gentle driving is generally possible while you arrange diagnosis, but emissions and fuel use may worsen. Stop if rough running becomes severe or power drops.
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.