OBD-II code · Powertrain (generic)

P01F1 O2 Sensor Circuit Bank 1 Sensor 4

Generic electrical fault on the bank 1, sensor 4 oxygen sensor (fourth sensor downstream — used on systems with multiple cat stages or NOx-trap diagnosis).

Is it safe to drive with P01F1?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelySensor failed

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

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.