P2274
O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 3
Fuel & air metering (O2 sensor)
Generic OBD-II
Low
What it means
P2274 means the third oxygen sensor on bank 1 is reporting a signal that is stuck or biased toward lean. This is a downstream sensor used to monitor catalytic-converter and emissions performance, not to control the fuel mixture, so the car normally drives fine. It usually points to a failing sensor, a wiring problem, or an exhaust leak near the sensor.
Low
Can I keep driving? Safe to drive — bank 1 sensor 3 is a downstream monitoring sensor, so this is mainly an emissions and check-engine-light issue.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable change in how the car drives
- May fail an emissions/readiness test
- Possible slightly higher fuel consumption
Common causes
Most likely first
- Failed or aged bank 1 sensor 3 oxygen sensorLikely
- Open, shorted, or corroded wiring/connector at the sensorCommon
- Exhaust leak upstream of the sensor drawing in airCommon
- Contaminated sensor (oil, coolant, or silicone)Less often
- Rarely, a genuine lean exhaust conditionLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for other fuel-trim or O2 codes first.
- Inspect the bank 1 sensor 3 connector and wiring for corrosion, damage, or a loose pin.
- Check the exhaust for leaks ahead of the sensor.
- Compare the sensor's live voltage against a known-good sensor with a scan tool.
- If the signal stays stuck lean with good wiring and no exhaust leak, replace the sensor. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2274?+
Yes. This sensor monitors the exhaust downstream of the catalyst and does not control fueling, so drivability is normally unaffected — but it should still be fixed to pass emissions.
Can I just clear P2274?+
You can, but it will come back within a few drive cycles unless the sensor, its wiring, or an exhaust leak is repaired.
Related codes
Often seen with P2274
Read & clear P2274 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX