P1151 O2 Sensor Fault in 2002 Ford Explorer 4.0L V6 - Engine Stalling at Stops or Reverse

I own a 2002 Ford Explorer with a 4.0L V6 engine and 5-speed automatic transmission. About a few months ago, the vehicle began stalling when coming to a stop light or when shifting into reverse or drive. The check engine light activated, and upon scanning, I found fault code P1151. I have already replaced the Mass Air Flow (MAF) sensor three times and the Idle Air Control (IAC) valve once. Despite these repairs, the stalling persists. I've also performed a thorough inspection for air leaks and completed a full tune-up. At this point, I'm considering whether the issue might be related to the torque converter. Can anyone provide insight into potential causes or diagnostic steps for P1151 in this specific model?