I have been researching good tuning shops in my local area (in Central FL), and came across Justin @ VMP Tuning. He really knows what he is talking about, and I'm definately taking my car to him when i get back from Iraq. One of the things he told me was to get some MotorCraft O2 Sensors before go in for the tune! He said that he has seen that other brands (such as Bosch) dont efectively heat like they should, and it can cause issues. Just a bit of info he passed to me (that I didnt know) so I figured I would pass to you... I hope all goes well! I know how frustrating it can be to have an issue that you just cant figure out, and to have the shop tell you "ya, thats all i can do"! See my "Help with tuning(?) issue" post for my story...Lol... Once again, best of luck!