i need to know how exactly to change the parameters for my new map sensor. do i need to load the cal file that my car is already tuned for? if so im screwed the tuner never gave it to me and i cant get ahold of him at all

 

Yes you need the existing kal.

You can hookup your laptop and try to download the kal directly from the ECU. Change the map sensor, save then reload. Careful though...I hear downloading directly from the ECU sometimes corrupts the kal.