P2276
O2 Sensor Signal Biased/Stuck Lean (Bank 2 Sensor 3)
O2 sensor at bank 2 sensor 3 reports a lean reading suspiciously stable for too long. Sensor 3 is typically downstream of the second catalyst on systems with three-stage aftertreatment.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Common causes
Ordered by how often each turns out to be the cause.
- Sensor agedCommon
Parts involved
- Oxygen Sensor
P2276 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.