Okay.. I tried running my JoeP MBC by itself (N75 taken out of the equation), and it worked fine when doing 100% throttle applications and during small amounts of throttle but when I went to about 1/2 to 3/4 throttle boost would jump up and down about 5psi.. It didn't want to hold boost above 5psi, and if I tried to force it, the EPC light would come on, and the car would shut down.. :)

Has anyone ever run into a similar problem? Im just trying to figure out if this is my cars own little problem (wastegate, boost leak..etc) or just an issue with the MBC.. If it comes down to it, im going to order a profec B II and call it a day, but I don't want to have similar problems with partial throttle applications..

with the wastegate/turbo sides looped together. Doing it this way I have had no problems with part throttle or WOT.

I had my N75 hooked up the same way.. The atmospheric side was left inside the intake track (wastegate and pressure hoses connected to the MBC), and I looped a tube from the wastegate end to the pressure side of the N75.. No problems with wOT until I exceeded requested boost by about 3psi at which point I went into limp mode.. :(

When the sensor reads a set boost over requested it will go into limp.