DTC P2198 - O2 Sensor Signal Biased/Stuck Rich (Bank 2 Sensor 1)

WARNING: This page does not describe the selected car, but rather 24 other vehicles, including the 2019 Lincoln Navigator, 2019 Lincoln Nautilus, 2019 Lincoln MKZ, 2019 Lincoln MKT, and 2019 Lincoln MKC. However, it is still accessible from the selected car via links, so may be relevant.

DTC DESCRIPTION P2198 - O2 SENSOR SIGNAL BIASED/STUCK RICH (BANK 2 SENSOR 1)

Description: A universal heated oxygen sensor bank 2, sensor 1 (HO2S21) indicating rich at the end of a test is trying to correct for an over rich condition. This DTC sets when the fuel control system no longer detects switching for a calibrated amount of time.
Possible Causes: Water in the harness connector UO2SPC21 circuit open Corrosion Incorrect connections Excessive fuel pressure Leaking or contaminated fuel injectors EVAP purge valve stuck open Biased MAP sensor signal Incorrect learned ethanol content Contaminated MAF sensor (if equipped) Positive crankcase ventilation (PCV) system Contaminated oil Oil overfill Camshaft timing Damaged universal HO2S21
Diagnostic Aids:
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to PINPOINT TEST H .