Have you "whacked" the MAP sensor with a screwdriver handle? If not try it and reset the ECU.

Nothing to loose but lots to gain.

 

Since your still in the factory warranty, you could always take it to the dealer to if all else fails.

 

I'm sorry, but that's going to do nothing for a misfire.

 

Thanks for all the info guys. The map sensor has nothing to do with it and unfortunately my vehicle is out of warranty by time not mileage. However, I've replaced the fuel filter and cleaned out the pump. I also added BG44 fuel system cleaner to a full tank of 94 unleaded to clean out the injectors. It's been a week, and about 15 or so trips, and the missfire has not returned (knock on wood).

Thanks again,
Phil