Common Checks
- Check for bank 2 vacuum leaks and exhaust leaks.
- Inspect upstream oxygen-sensor wiring and connector condition.
- Compare bank 1 and bank 2 fuel trims.
Diagnostic trouble code
P2197 Bank 2 Sensor 1 Oxygen Sensor Signal Biased/Stuck Lean
The upstream oxygen sensor signal on bank 2 appears stuck lean or biased lean.
Fuel Trim & Mixture CodesCommon Repairs
- Repair leaks or wiring faults.
- Replace the upstream bank 2 oxygen sensor only after confirming the signal is biased.
Mustang Notes
- Bank-specific lean bias can help separate a localized leak from a whole-engine MAF or fuel-pressure issue.
Model-Year Applicability
Listed for 1996 and newer traditional gasoline Mustang pages in this first-pass catalog. Engine, calibration, and Ford-specific codes may narrow that range as more service data is added.