so im going to go get my truck dynoed on monday, but i dont have my new maf from sct yet, and i dont think it will be in by monday. do they need it for the dyno to get the right numbers or can they use the stock one and i can put it on later and go in my x3 and change the maf meter?

 

You'll probably have to take it back. The "SCT" meter requiers a whole new set of parameters to properly use and I know the SCT XCal2 doesn't have any "selection" process for it or the kind of "end user" adjustability to do it.

 

I would wait and have the piece in place.