Well actually there is boost but the needle has stopped moving. I just sits right below 0 on the gauge. It does do the swipe when the car is started other than that is doesnt move at all. How is the PSI read? My guess would be vacuum.
MAP sensor. Turns the vacuum analog signal into a signal the PCM can read and pass on to the boost gauge. Check the vacuum lines around your MAP sensor (not sure on the S2 location, but probably near your FPR) and check the vacuum lines under the snout of the SC. S1 doesn't have one there, but you do.
There are two MAP sensors on the back side of the engine, above the rear valve cover. Lines run from the SC snout, behind the alternator and to the MAP snesors. First sensor in line has a T-fitting and the line continues to an elbow at the second sensor. The fittings and line are underneath each sensor