anyone know about transmissions???

I don't see anything in your sig that should cause that kind of problem but who knows. If you plan on adding a blower or running nitrous I would get a built trans just so you don't have this problem again. I'm not sure what to suggest though since I'm not up to date on Ford auto transmissions. What about a nice TH400?

how many miles on it , just to see before you spend the $$ on it , why dont you unhook one of the cooler lines and run a hose in a big bucket , and get about 3 gallons of tranny fluid , start and stop the car for a few seconds while adding new fluid try to keep the fluid level the same as what you add as what pumps out , might have to add or let some pump out when you get done but make sure you run about 3 gallons through it , the hose will pump the old fluid the in bucket , do this first and then unhook the battery for 5 minutes when you get done , and see if the code comes back , then drive it and see if it fixes it , you would be surprised what new fluid can do especially when you flush the whole system like im talking about , if that doesnt help , dont waste $$ on bandaids , get a built tranny for it .