Ok, when I got my car back from the shop, I noticed my idle was a little higher than usual, idles around 1000rpm now. I thought it was just because it was hot, which it tends to do, but now I hear a very low hiss from my bypass valve at all speeds, which leads me to believe I have a bypass valve leak/vacuum leak in my manifold. How can I pinpoint the leak? Am I loosing boost/power because of it?

 

The bypass valve will bleed off boost unless you're at wide open throttle. Have you looked at it to see if the vaccum line is connected? Do you have a boost gauge? Bob