Finally got my Explorer to the dealer to troubleshoot the P160A code. They used the above information that I found on the internet to reconfigure the PCM properly and do the "relearn" procedure. They also said everything "looked good and it was running fine".
...within a mile of driving away from the dealer, while waiting at a stop light - the idle started to act up again and go down below 500RPM's. I immediately turned around and drove back to the dealer - stopping at an AutoZone on the way there to "rent" a scanner. Also, while driving it back to the dealer, the engine started cutting in and out as though it was misfiring but this time I was also seeing the Check Engine Light (CEL) blinking. That was actually something of a good sign this time...because the P160A code was causing me to not have any CEL's as it was erasing any codes upon each startup.
The dealer was getting ready to close so I turned the vehicle back into the remaining service writer to leave for tomorrow morning for them to take a look at it. I also hooked up the scanner in the parking lot and I had a P0301 code (Misfire Cylinder #1) show up - one of the same codes I originally had when this ordeal started back in September.
Back in September, the dealer said it was a shorted out PCM that was causing a misfire to Cylinder #1 and they replaced the PCM under warranty and the vehicle has operated just fine for the past three or so months. I'm at a loss as to what could cause this to possibly come up again. If the dealer was not as far away as it is...I'd do some more troubleshooting on my own to rule out the spark plug, coil, and injector again before letting them look at it.