wastegate stuck open runing 5 psi how to fix it for cheap
aftermarket wastegate actuator. skim ebay for them cant remember what I gave for mine.... make sure you get one with a bracket
Is the WGA rod stuck? If not you should be able to adjust it so that the waste-gate puck is closed. There should be about half of the diameter of the hole that the swing arm goes into worth of pressure. So that you have to pull the rod a bit to get it all hooked up.
If your diaphragm is wasted or the rod is stuck your going to have to replace the waste gate actuator.