DTC P2271 - O2 Sensor Signal Biased/Stuck Rich (Bank Sensor 2)

WARNING: This page does not describe the selected car, but rather 26 other vehicles, including the 2020 Lincoln Navigator, 2020 Lincoln Nautilus, 2020 Lincoln MKZ, 2020 Lincoln Corsair, and 2020 Lincoln Continental. However, it is still accessible from the selected car via links, so may be relevant.

DTC DESCRIPTION P2271 - O2 SENSOR SIGNAL BIASED/STUCK RICH (BANK SENSOR 2)

For CorsairEdgeEscape/Kuga, 2.0LExplorer, 2.3LNautilusRanger, 2.3LTransit Connect, 2.0L
Description:	This DTC sets when the heated oxygen sensor bank 1, sensor 2 (HO2S12) signal is greater than the calibrated lean value during the current key cycle and, after three consecutive intrusive events, the signal cannot be forced less than the calibrated lean value.
Possible Causes:	Aftermarket exhaust accessories or performance modifications Ethanol content in the fuel HO2S12 circuit intermittent Damaged HO2S12
Diagnostic Aids:	Check for leaks in the exhaust system. Check for an intermittent HO2S12 signal.
For All Others
Description:	The heated oxygen sensor bank 1, sensor 2 (HO2S12) is forced rich and lean and monitored by the PCM. This DTC sets when the PCM does not detect the output of the HO2S in a calibrated amount of time.
Possible Causes:	Pinched, shorted, and corroded wiring and pins Crossed HO2S12 wires Exhaust leaks Contaminated HO2S12 Damaged HO2S12
Diagnostic Aids:
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
Corsair, Edge, Escape/Kuga 2.0L, Explorer 2.3L, Nautilus, Ranger 2.3L, Transit Connect 2.0L	GO to PINPOINT TEST DW .
All others	GO to PINPOINT TEST H .