P1151 Fault Code on 2001 Ford Explorer Sport Trac: Loss of Power and O2 Sensor Diagnosis

Last night while driving home, I experienced a sudden and severe loss of engine power. When I pressed the accelerator, there was no response at all, and the engine produced a noticeable knocking sound. The Malfunction Indicator Lamp (MIL) did not illuminate. Using a scan tool, I detected fault code P1151 — Manufacturer Control: Fuel Air Metering — which indicates a 'HO2S Bank 2 Sensor 1 Insufficient Switching Lean/Lean' issue. I researched this code and found that it typically relates to the oxygen sensor in bank 2, sensor 1, failing to properly detect lean or rich conditions. I’ve reviewed a list of common troubleshooting steps from various automotive forums, but I’m still looking for reliable guidance. My plan is to inspect the O2 sensor tomorrow. If replacing the sensor resolves the issue temporarily, and the code reappears with a different value, it may confirm the sensor as faulty. Is this an effective way to test the O2 sensor? Any additional insights or suggestions would be greatly appreciated. Interestingly, my vehicle has exhibited similar symptoms of power loss about 3–4 months ago, but no diagnostic codes were present at that time. Thanks in advance for any help — I'm hoping to resolve this before it becomes a safety concern. Regards, Steve