P0167 fault code: O2 Sensor Heater Circuit

P0167 means “O2 Sensor Heater Circuit” — a fuel and air metering fault in the powertrain.

Can I DIY?

Professional-only boundary. Not DIY: oxygen-sensor heater circuits need a workshop, not a parts-cannon.

Do not DIYReviewed page boundary

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 P0167

Do not drive. The heater that brings an oxygen sensor up to working temperature is not matching what the computer expects. A cold sensor is slow to report exhaust oxygen, which delays closed-loop fuelling.

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 Heater Circuit: Number plate
  • O2 Sensor Heater Circuit: Exact code P0167 and any other heater or oxygen-sensor codes
  • O2 Sensor Heater Circuit: Recent exhaust or underbody work, if any
P01xxFuel and air metering
MOT fail riskif the warning light stays on

What does P0167 mean?

P0167 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 Heater Circuit”. The code itself tells you which circuit or system tripped the fault — not always the exact part that failed.

Will P0167 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.
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P0167 — quick answers

Is it safe to drive with P0167?

Do not drive. P0167 has no verified driving guidance. Do not drive until a workshop has checked the heater circuit. This is a heater-supply fault, not a 'no activity' signal fault and not a fuel-rail pressure code.

Will P0167 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.