to much boost?

[3.0Duster]

i finally fixed my exhaust manifold gasket so my exhaust system has no leaks now, but now im getting about 18psi of boost, is that to much to run on the vnt, how do i go about backing it off, even at half throttle it goes upto 18psi, i would like to set up a system with a switch where i can specify like 8psi and then flip a switch and get max boost, does the actuator work the same way as the wastegate where i can set up a valve solenoid to set boost?, thanks