I know I dont always have tactful way of saying things. 
Maybe the wastegate puck is sticking or something. Have you pulled back on it and tried to move it forward and back to make sure its not sticking?
What are you using to control boost? Is it plumbed up tuner style, or to the factory solenoid, or to a pressure regulator?
Go pick up a 0-30 or 0-25psi pressure regulator from mcmaster.com. Run the hose that normally goes to the factory solenoid, to the outgoing port on the regulator. Youll see an arrow showing the direction for flow. Dont plumb it to the arrow pointing in. Take it to the port that would be going out. Plug the 2 ports on the sides with 1/8"NPT pipe plugs, (also order this from mcmaster, and even get some silicone tubing if you want) and leave the one that shows the arrow going in, open. Turn the knob all the way clockwise, and then back off about 5 full turns. Take it for a run, and adjust the boost according to what you get. Clockwise to up the boost, counter to reduce it. I had some boost spiking issues when I had it hooked to the factory solenoid, and now everything is very well controlled, and it also spools MUCH faster than it used to. Plumbing the hose up in the reverse order from what i said still works, but for some reason there is alot more turbo lag when its plumbed up "the right way".
Maybe the wastegate puck is sticking or something. Have you pulled back on it and tried to move it forward and back to make sure its not sticking?
What are you using to control boost? Is it plumbed up tuner style, or to the factory solenoid, or to a pressure regulator?
Go pick up a 0-30 or 0-25psi pressure regulator from mcmaster.com. Run the hose that normally goes to the factory solenoid, to the outgoing port on the regulator. Youll see an arrow showing the direction for flow. Dont plumb it to the arrow pointing in. Take it to the port that would be going out. Plug the 2 ports on the sides with 1/8"NPT pipe plugs, (also order this from mcmaster, and even get some silicone tubing if you want) and leave the one that shows the arrow going in, open. Turn the knob all the way clockwise, and then back off about 5 full turns. Take it for a run, and adjust the boost according to what you get. Clockwise to up the boost, counter to reduce it. I had some boost spiking issues when I had it hooked to the factory solenoid, and now everything is very well controlled, and it also spools MUCH faster than it used to. Plumbing the hose up in the reverse order from what i said still works, but for some reason there is alot more turbo lag when its plumbed up "the right way".
