Boost problem

Well maybe some of you remembered that my car would not boost over 9psi.
Well I though it was my boost controller installed uncorrectly but it wasnt. Took it to a shop and it was reinstalled and the car wouldnt boost over 9psi. Bought Greddy couplers and huge T-bolts so I am sure I have absolutly no boost leaks. OK, any one out there that can think of something that can stop me from boosting high and keeping me low at 9psi. Also my friends evo has a greddy profec b or something and a delphi boost gauge and he gets about 20psi at around 3000rpms and I get like 9psi at almost 6k. OK wtf, turbo is new, no exhaust leaks(i think) Wastegate malfuntioning or something. Any one out there that can throw any ideas I need em pls.

Thanks guys

Could be a wastegate problem. Check it and make sure it is sealing off the hole, and that the preload is set correctly on the WGA. (I about read that today thanks Kevin)

OK, how do i check the WGA again ?

Nice! We're definitely getting my money's worth out of that post... :D