Is it really necessary to pull the fuses out to program a tune into truck.??????

well, they claim that it could interfere with some of the functions in
your truck so its more of a precautionary thing. ive done this
both ways and havent had a problem yet, knock on wood...

Sometime when you try to install the programmer when the fuses are in place it will interfere with the OBD port and not allow the codes to uploaded. Just safer to pull them and not worry about it while you are trying to install the programmer...