Thanks for the replies. It was definitely the PCM they replaced, with a used one that they took to a dealer and had flashed. When I was having the same exact symptoms last winter, I went to a mechanic and rode with him during the road test. Even he wasn't sure what was going on with the car, there were no codes activated but there were two strange things going on during the road test (the first was that the gear on his reader would show we are in a different gear than the car was actually in, and I don't remember the second problem). Anyways, he figured it might be the TPS or PCM, which he replaced them both. That worked for about ten months.
About the wiring, isn't that something the mechanic would have noticed last winter? If I check it myself, and unplug it, will that screw anything up where I would have to reset everything or take it into a shop to get reset?
And I looked in my Haynes manual and it says it doesn't have a MAF sensor, only the V6 models have it (mine is a 2.4 L 4 cyl).