I had a Greddy Profec B Spec II also, and jesus that thing was the most confusing annoying boost controller i ever used. Having to set the wastegate opening pressure, the gain, etc. I could NEVER (repeat) NEVER got my boost stable. It always creeped or fell off or something. Granted that was probably cause i had a 57trim inducer wheel on my stock turbo. My inlet was bigger than the exhaust outlet so that probably didnt help.