P2273
O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 2
Fuel & air metering (emissions)
Generic OBD-II
Medium
What it means
P2273 means the downstream oxygen sensor on Bank 2 (the one after the catalytic converter) is reporting a signal stuck or biased rich. Because this sensor mainly watches converter efficiency rather than controlling fueling, the car usually drives normally, but emissions monitoring is affected until it is fixed.
Medium
Can I keep driving? Generally safe to drive — this is the downstream sensor, so drivability is usually normal, but the fault should be fixed to keep emissions and the converter monitor working.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable change in how the car drives
- Slightly higher fuel consumption in some cases
- May fail an emissions test
Common causes
Most likely first
- Failed or aged Bank 2 Sensor 2 (post-catalyst) oxygen sensorLikely
- Sensor contaminated by oil, coolant, or siliconeCommon
- Corroded connector or damaged wiring at the sensorCommon
- Exhaust leak near the downstream sensor skewing the readingLess often
- Genuinely rich exhaust from an upstream fueling faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for upstream fuel-trim or misfire codes first.
- Inspect the Bank 2 Sensor 2 connector and wiring for corrosion or damage.
- Check for exhaust leaks ahead of the downstream sensor.
- View live O2 data — a flat, stuck-high signal points to the sensor.
- Replace the downstream Bank 2 Sensor 2 if it stays biased rich, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2273?+
Yes, in most cases the car drives normally. Repair it so the vehicle passes emissions and the converter monitor stays accurate.
Can I just clear P2273?+
It will come back within a few drive cycles unless the downstream sensor or its wiring is repaired.
Related codes
Often seen with P2273
Read & clear P2273 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