Error code

OBD2 P2271

OBD2P2271
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

O2 Sensor Signal Stuck Rich.

Severity

moderateCan drive, but may experience slight roughness and potential emissions test failure.

Summary

Code P2271 indicates that the heated oxygen sensor (H02S) #2 on bank 1 is sending a signal indicating a constant rich-running condition, which means there's too much fuel in the exhaust.

Symptoms

  • Illuminated warning light
  • Stored trouble code
  • Multiple additional codes associated with unrelated systems or components may be present
  • Some readiness monitors may not initiate or complete successfully
  • In rare cases, slight engine roughness at certain speeds
  • Vehicle may fail an emissions test

Common Causes

  • Defective downstream oxygen sensor
  • Contaminated downstream oxygen sensor
  • Faulty catalytic converter
  • Excessive fuel pressure
  • Damaged or leaking fuel injectors
  • Engine coolant leaks affecting the oxygen sensor's reference air
  • Oil contamination of the oxygen sensor’s reference air

Diagnosis

  1. Inspect wiring and connectors for damage or corrosion
  2. Check fuel pressure and injectors for proper function
  3. Verify catalytic converter condition
  4. Test downstream oxygen sensor for functionality

Fixes

  • Replace the faulty downstream oxygen sensor

FAQ

What does a stuck rich signal mean?

A 'stuck rich' signal means that the oxygen sensor is indicating too much fuel in the exhaust, which can be caused by issues like a faulty sensor or excessive fuel pressure.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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