P1151 Fault Code in 1999 Ford Ranger: How to Fix Lean Condition in Bank 2
I recently noticed the check engine light coming on in my 1999 Ford Ranger. After using a code reader, I identified the fault code P1151. This code indicates a lack of signal from the upstream O2 sensor (O2S21) on Bank 2, which suggests a lean air-fuel mixture. Given the age of this vehicle, the most likely cause is a failing upstream oxygen sensor on Bank 2. I'm seeking advice on how to properly diagnose and fix this issue. Any insights or recommendations would be greatly appreciated.
P1151 = Lack of signal from the upstream O2 sensor (O2S21) indicating a lean condition. For a 1999 Ford Ranger, this typically points to a failing upstream oxygen sensor on Bank 2. Replacement is recommended; however, it's best to source the part directly from a Ford dealership rather than an aftermarket supplier to ensure compatibility and proper function.