P2631
O2 Sensor Pumping Current Trim Circuit High Bank 2 Sensor 1
Emissions / oxygen sensor
Generic OBD-II
Low
What it means
P2631 is a wideband (air/fuel ratio) oxygen sensor fault — the pumping-current trim circuit for bank 2, sensor 1 is reading high. That upstream sensor helps the computer fine-tune the fuel mixture, so a circuit fault can slightly upset fuel trim and emissions. It does not cause a no-start and rarely affects everyday drivability.
Low
Can I keep driving? Yes — this is an oxygen-sensor circuit fault. The engine starts and runs normally; expect a check-engine light and possibly slightly worse fuel economy or emissions.
Common symptoms
What you'll notice
- Check-engine light on
- Slightly reduced fuel economy
- Possible faint rough idle or mild hesitation
- May fail an emissions test
Common causes
Most likely first
- Faulty bank 2 sensor 1 air/fuel (wideband O2) sensorLikely
- Open, shorted, or corroded wiring or connector at the sensorCommon
- Swapped or miswired upstream O2 sensor connectors (often after a prior repair)Common
- Poor sensor ground or referenceLess often
- Faulty ECM/PCM (least likely)Less often
How to diagnose & fix
Work through it in order
- Confirm the code and check for related O2 trim codes (P2629, P2630).
- Verify the bank 2 sensor 1 connector isn't swapped with bank 1 — check recent repair history.
- Inspect the sensor wiring and connector for damage or corrosion.
- Check the sensor's circuit values against spec; replace the air/fuel sensor if it's out of range.
- If the sensor and wiring are good, suspect the ECM.
FAQ
Quick answers
Is it safe to drive with P2631?+
Yes. It's a sensor-circuit fault — the car starts and drives. You may lose a little fuel economy and could fail emissions until it's fixed.
Can I just clear P2631?+
It comes back within a few drive cycles unless the sensor or wiring is repaired.
Related codes
Often seen with P2631
Read & clear P2631 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