Bob's Mechanical Repairs

P2271 — O2 Sensor Signal Stuck Rich (Bank 1, Sensor 2)

Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email [email protected].

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The post-cat oxygen sensor is stuck reading rich. It could be the sensor, or the engine genuinely could be running rich.

P2271 — also written P2271, P 2271, 2271 — is the OBD-II code for o2 sensor signal stuck rich (bank 1, sensor 2). Same code, same fix: this page covers every spelling of it.

P2271 is a emissions fault code, typically costing £90–£400 to put right in a UK garage.

What causes P2271?

  • Failed rear O2 sensor
  • Genuinely rich mixture from a leaking injector
  • Contaminated sensor from oil or coolant burning
  • Short to voltage in the signal wire

How P2271 is fixed

  • Check fuel trims before replacing the sensor
  • Replace the rear O2 sensor
  • Investigate any injector leak or oil consumption

P2271 repair cost in the UK

Most P2271 repairs land between £90–£400 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.

Can you drive with P2271?

Yes, but a rich mixture wrecks catalytic converters over time.

Urgency: medium.

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