i Just had my car in service for a rattleing under full boost. They determined that it was the boos guage and replaced that and the turbo and exhaust manifold gaskets. now my car goes to 28lbs of vaccum is that normal? it used to idle at 18lbs of vaccum and now it spkies 17 and slowly tapers off to redline. it never used to do that before? what does a stoc srt 4 normaly have for vaccum? any help or replies would be great. thanks!