edit: solved. vacuum lines were somehow swapped =X

 

that happened to me when i had my gizzmo boost controller, but i fixed it by changing my wastegate gain %, idk how you would fix that with a MBC

 

I don't think it was going as low as it is prior to installing the MBC, either. It's definitely installed correctly b/c we turned it the other way and it was just hovering at 10 PSI without any flutter.

All the lines are good and such, but I just don't understand why it would taper so low after peaking.

 

I added some more info to the OP.

Would a tune maybe help with this or is it a problem with the MBC itself?