P0191 fault code: Fuel Rail Pressure Sensor Circuit Range/Performance

Last updated · OBDCode UK editorial

Can I drive with P0191? — Limit driving

Our verified driving guidance for P0191 is limited driving: make only essential short journeys if the engine runs without misfire, smoke, or fuel smell. Do not open the rail. Hot high-pressure fuel can scald.

P0191 means “Fuel Rail Pressure Sensor Circuit Range/Performance” — a fuel and air metering fault in the powertrain. Limit driving. The fuel-rail pressure sensor is reporting a value that does not match expected range or performance. Opening a high-pressure rail is not DIY; a parked scanner read is a separate non-invasive check.

Can I DIY?

Do not DIY this repair. We do not publish DIY repair or strip-down steps for this code on this page. Read codes and observe only; leave the repair to a qualified garage.

Do not DIY this repairDIY boundary
ToolsSpecialist tools or workshop equipment — typically a professional garage job.

This fault is in the professional-only category. We do not publish strip-down or fitting steps on this page. Use a qualified garage.

Hot systems

Never open a hot coolant cap — pressure can scald you. Exhaust and catalytic converter get hot enough to burn and ignite debris. Stay clear of electric fans; they can run after shut-off.

P01xxFuel and air metering
MOT fail riskif the warning light stays on

What does P0191 mean?

P0191 is a generic (SAE standard) powertrain code reported by your car’s engine control unit. It sits in the P01xx block, which covers fuel and air metering. The stored description is “Fuel Rail Pressure Sensor Circuit Range/Performance”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0191 fail an MOT?

An illuminated engine management light is a Major defect at MOT (automatic fail) until the fault is repaired and the light stays off.

Before booking your test, check what usually fails on your car: see our MOT pass rates by make and model, built from 33.1 million DVSA tests.

What the MOT data says

No MOT certificate item corresponds to this code; MOT outcome data cannot be shown.

Related guides

Car diagnostic test cost: compare the scopeUK booking marketplaces currently publish diagnostic averages of about £52–£65. Engine management light on: steady or flashing?A steady engine management light means the computer has stored a fault. Drive with caution and get the code read. A flashing light is different — stop when it is safe.
P0100Mass or Volume Air Flow Circuit P0101Mass or Volume Air Flow Circuit Range/Performance P0102Mass or Volume Air Flow Circuit Low Input P0103Mass or Volume Air Flow Circuit High Input P0104Mass or Volume Air Flow Circuit Intermittent P0105Manifold Absolute Pressure/Barometric Pressure Circuit P0106Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance P0107Manifold Absolute Pressure/Barometric Pressure Circuit Low Input

P0191 — quick answers

Is it safe to drive with P0191?

Limit driving. Our verified driving guidance for P0191 is limited driving: make only essential short journeys if the engine runs without misfire, smoke, or fuel smell. Do not open the rail. Hot high-pressure fuel can scald.

Can I fix P0191 myself?

Do not DIY this repair. We do not publish DIY repair or strip-down steps for this code on this page. Read codes and observe only; leave the repair to a qualified garage. Specialist tools or workshop equipment — typically a professional garage job.

Will P0191 fail my MOT?

An illuminated engine management light is a Major defect at MOT (automatic fail) until the fault is repaired and the light stays off.

Fault-code identifiers are standard diagnostic facts. Their explanations and diagnostic guidance on this site are original editorial summaries, not reproduced SAE wording. MOT defect rules reflect the DVSA MOT inspection manual (2026). This page is general guidance for UK drivers, not a substitute for a professional diagnosis.