What P2271 means
The downstream sensor's signal is stuck at a rich reading rather than responding to exhaust changes.
Common causes
- Failed downstream oxygen sensor
- Sensor contamination from coolant or oil burning
- Wiring short
How it is usually fixed
- 1Inspect wiring
- 2Address any oil or coolant consumption
- 3Replace the sensor
Other common codes
- P0011 — Camshaft Position A – Timing Over-Advanced (Bank 1)
- P0030 — HO2S Heater Control Circuit (Bank 1, Sensor 1)
- P0101 — Mass Air Flow Circuit Range/Performance
- P0113 — Intake Air Temperature Sensor Circuit High
- P0118 — Engine Coolant Temperature Sensor Circuit High
- P0131 — O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)
Code information is general guidance, not a diagnosis for a specific vehicle. Confirm with live data and manufacturer test procedures before replacing parts.