dont go to the dealership
My first bit of advise would be to not listen to anything the dealship has to say. I dont think they can even know what the pcm does. I had one dealership tell me that the pcm had nothing to do with any of the problems i was having. But no, My check engine light did not come on until 3 to 4 months after my problem started, and it did not stay on. And their diagnostics are just as crappy as their pcms. They will tell you it is the coil, crank shaft sensor, distributor, rotary, and the list will go on and on, as will the bill. The best advice i got was from these forums. check out the other threads, read them and just go ahead and change the pcm and o2 sensor. it will save you hundreds of dollars in useless repairs and tons of time. and dont spend hundreds on a mechanic to do it for you. on the other thread that has over 600 post you can find how to change it your self, it is simple and easy to do. I done mine myself and know absolutely nothing about vehicles. i could not change my own oil if i had to, but i changed the pcm all by my lonesome self going by the advice of people on here. Much more than i got from the dealership or any mechanic.