The great wall of 4200-4500 rpm

[dyermullet]

the proper way to use seafoam on a turbo buick is 
 start the car
let it warm up
throw the seafaom in the trash
drive the car

It is a lot easier and quicker to check for exhaust leaks than to pull the ps manifold for no reason.

[PacecarTA]

a length of hose held to your ear will find it easier

btw if you can make boost then  even if you have a leak its not affecting performance or have any effect on the Airfuel (or O2 reading)  , may slow spool but once you have your boost doesnt matter