I thought the over boost pressure switch was mounted to the firewall over towards the alda, and has a vacume line going from the banjo bolt at the back of the manifold on one side, the alda on the other.
The part I am wondering about is simply a sensor screwed into the intake manifold. It has an electrical connector, no vacume line. Unfortunately i have no way of photographing it, but when I look at Fast Lane they have a part called a boost sensor that looks like it. I am reaaly curious as to what exactly it does. I did not trace where the wire runs to. Does it send the signal to the overboost protection switch?