P2271 - O2 Sensor Signal Biased/Stuck Rich (Bank 1 Sensor 2)

DTC DESCRIPTION P2271 - O2 SENSOR SIGNAL BIASED/STUCK RICH (BANK 1 SENSOR 2)

For Bronco Sport, 2.0L Corsair Edge Escape/Kuga, 2.0L Explorer, 2.3L Nautilus Ranger, 2.3L Transit 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
Bronco Sport 2.0L, 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.