OBD-II code · Powertrain (generic)

P0191 Fuel Rail Pressure Sensor Circuit Range / Performance

The fuel rail pressure sensor signal is within electrical limits but doesn't match commanded rail pressure under various engine loads. Common in common-rail diesel and GDI petrol engines.

Is it safe to drive with P0191?

Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.

Common causes

  • Most likelyPressure sensor drifted
  • PossiblePressure regulator stuck
  • Less likelyHigh-pressure pump worn

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
1–6 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Fuel Rail Pressure Sensor, High Pressure Pump, Rail Pressure Regulator

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