I have had the same exact issues with my 02 Explorer. When i read your post i got so excited because we have been trying everything to figure out the problem! Now i haven't checked it out yet but pretty positive tart this could be our solution as well. We got the coffee for a #4 misfire and at the same time the AC started acting up and then we got the po354 code. I'm going check it this morning and I'll post the results.