P2248
O2 Sensor Reference Voltage Performance Bank 2 Sensor 1
Fuel & air metering (O2 sensor)
Generic OBD-II
Medium
What it means
P2248 means the reference voltage feeding the upstream wideband air-fuel (O2) sensor on bank 2, sensor 1 is out of its expected range. That reference lets the sensor accurately measure the exhaust mixture; when it drifts the ECM runs open-loop, so the car stays drivable but may idle rough and use a little more fuel until the sensor or its wiring is corrected.
Medium
Can I keep driving? Drivable — with the upstream sensor circuit faulted the ECM runs open-loop, so expect slightly worse economy and possibly rough idle, but no stalling risk.
Common symptoms
What you'll notice
- Check-engine light on
- Slightly rough or uneven idle
- Increased fuel consumption
- Minor hesitation or surging
Common causes
Most likely first
- Faulty upstream air-fuel ratio (wideband O2) sensor, bank 2 sensor 1Likely
- Reference voltage circuit out of range — wiring open, shorted, or high-resistanceCommon
- Poor or corroded connection at the sensorCommon
- Faulty ECM/PCM reference supplyLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and check for companion sensor codes (P2247, P2249, P2250).
- Inspect the bank 2 sensor 1 connector and wiring for corrosion, chafing, or exhaust-heat damage.
- Measure the sensor's reference voltage circuit and compare it to spec.
- Confirm the ECM is supplying a stable reference voltage to the sensor.
- If the wiring and reference are good, replace the bank 2 sensor 1 air-fuel/O2 sensor and retest.
FAQ
Quick answers
Is it safe to drive with P2248?+
Yes, for the short term. The car runs in open-loop with slightly worse economy, but there is no stalling risk; repair it before it affects emissions or the catalyst.
Can I just clear P2248?+
It returns until the sensor or its reference-voltage circuit is repaired, since the ECM checks that reference whenever the sensor is active.
Related codes
Often seen with P2248
Read & clear P2248 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