P0093 fault code: Fuel System Leak Detected - Large Leak

P0093 means “Fuel System Leak Detected - Large Leak” — a fuel and air metering fault in the powertrain.

Can I DIY?

Professional-only boundary. Do not hunt a large fuel leak yourself; confirm P0093 and recover the car.

Do not DIYReviewed page boundary
ToolsSpecialist equipment

This is the conservative boundary from the reviewed code record. This page has no frozen site-wide safety grade, so it does not publish a repair route.

What to tell the garage about P0093

Do not drive. The computer has flagged a large leak in the fuel system. Wet fuel and vapour are fire and fume risks, not a minor emissions curiosity.

Take these reviewed, code-specific details with you. They help the garage confirm the fault without turning this page into a repair procedure.

  • Fuel System Leak Detected - Large Leak: Registration number
  • Fuel System Leak Detected - Large Leak: Exact code P0093 and any other fuel or EVAP codes from the same scan
  • Fuel System Leak Detected - Large Leak: Where you first noticed smell, wet fuel, or a stain
  • Fuel System Leak Detected - Large Leak: Whether the engine was left idling after the light came on
P00xxFuel and air metering
MOT fail riskif the warning light stays on

What does P0093 mean?

P0093 is a generic (SAE standard) powertrain code reported by your car’s engine control unit. It sits in the P00xx block, which covers fuel and air metering. The stored description is “Fuel System Leak Detected - Large Leak”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0093 fail an MOT?

An illuminated engine management light is a Major defect at MOT until repaired and the lamp stays off. A fuel leak can separately fail as a dangerous defect; P0093 is the computer's leak flag, not a DIY pass.

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.

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.
P0001Fuel Volume Regulator Control Circuit/Open P0002Fuel Volume Regulator Control Circuit Range/Performance P0003Fuel Volume Regulator Control Circuit Low P0004Fuel Volume Regulator Control Circuit High P0005Fuel Shutoff Valve 'A' Control Circuit/Open P0006Fuel Shutoff Valve 'A' Control Circuit Low P0007Fuel Shutoff Valve 'A' Control Circuit High P0008Engine Position System Performance

P0093 — quick answers

Is it safe to drive with P0093?

Do not drive. We have no verified driving guidance for P0093 — treat as do not drive until checked. A large fuel leak is a fire and vapour hazard; do not keep running the engine to 'find' it.

Will P0093 fail my MOT?

An illuminated engine management light is a Major defect at MOT until repaired and the lamp stays off. A fuel leak can separately fail as a dangerous defect; P0093 is the computer's leak flag, not a DIY pass.

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.