ok i ran the trouble codes all i got was a 12 and a 55 the check engine light isnt on so i went to the dealer and all they can tell me is to come in and have a diagnostic ran. but that was nothing new they just want your money. so im lost i have done everything but jack up the radiator cap and replace everything underneath it. the only thing i havent done yet is replace what looks like the fuel filer on the body under the damn thing. its starting to make me pretty mad cause i know im not stupid cause i do all my own work cause i cant really afford to pay someone else. would a burnt plug make it do the same thing cause i was checking the tranny fluid today like i do once a week and im under the hood and it dies just like i turned the key off. no spitting or anything just stopped running. so i dont know what to do here

but if you guys can think of anything else it would be greatly appriciated

thanks again

Marty