OBD-II code · Powertrain (generic)
P01F2 O2 Sensor Circuit Low Voltage Bank 1 Sensor 4
Bank 1 sensor 4 O2 sensor signal voltage below expected range — short to ground or sensor stuck low.
Is it safe to drive with P01F2?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor B1s4, Sensor Wiring
Related codes
- P01EFEngine Coolant Heater B Control Circuit Performance
- P01F0Coolant Temperature Relapsed Below Diagnostic Monitoring Temperature
- P01F1O2 Sensor Circuit Bank 1 Sensor 4
- P01F3O2 Sensor Circuit High Voltage Bank 1 Sensor 4
- P01F4O2 Sensor Circuit Slow Response Bank 1 Sensor 4
- P01F5O2 Sensor Circuit No Activity Detected Bank 1 Sensor 4
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.