P0150 fault code: O2 Sensor Circuit

P0150 means “O2 Sensor Circuit” — a fuel and air metering fault in the powertrain.

Can I DIY?

Professional-only boundary. Confirm P0150 names bank 2; swapping the wrong-bank probe is not DIY here.

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 P0150

Do not drive. The upstream oxygen probe on bank 2 — the other cylinder bank on a V or boxer layout — has a circuit fault. Bank 2 is not bank 1; this is the pre-catalyst probe on that second bank.

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

  • O2 Sensor Circuit: Registration number
  • O2 Sensor Circuit: Exact code P0150 and any companion codes
  • O2 Sensor Circuit: Whether the engine management light is steady or flashing
  • O2 Sensor Circuit: Which cylinder bank the garage treats as bank 2 on this engine family
P01xxFuel and air metering
MOT fail riskif the warning light stays on

What does P0150 mean?

P0150 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 “O2 Sensor Circuit”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0150 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.

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

P0150 — quick answers

Is it safe to drive with P0150?

Do not drive. We have no verified driving guidance for a bank-2 upstream oxygen-circuit flag. Do not copy bank-1 heater advice onto this page. Treat as do not drive until a garage scans bank 2.

Will P0150 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.