P01F5
O2 Sensor Circuit No Activity Detected Bank 1 Sensor 4
Generic OBD-II
Real-world scan data
Seen in
41
scans in the past year
Found in
<0.1%
of scans
<0.1%
of scans that found faults
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check the O2 sensor wiring for any loose connections or damage.
- Replace the O2 sensor for Bank 1 Sensor 4.
- Inspect the exhaust system for any leaks or blockages.
- Reset the OBD 2 error code using the scan tool or disconnecting the battery.
- Perform a complete diagnostics to assess other potential issues with the vehicle's engine or emission system.
Common causes
Most likely first
- Faulty oxygen sensor
- Wiring issues or loose connections in the oxygen sensor circuit
- Engine misfire or poor fuel mixture
- Exhaust system leak or damage
- Faulty engine control module (ECM)
How to diagnose & fix
Work through it in order
- Check engine light is illuminated on the dashboard
- Decreased fuel efficiency or poor gas mileage
- Rough or uneven engine idling
- Engine misfires or stumbles
- Poor acceleration or lack of power
Read & clear P01F5 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.