You stated previously that you had a problem with the boost spiking before the car goes into redline, correct? Anyone on this forum should have told you that boost spiking in the MSP is pretty common. Also, I am having a similar problem with oil leakage on the turbo. However, I know that my turbo is wearing out and I will be replacing it pretty soon.
The only think I could suggest is to replace the stock turbo with another, such as the Garrett GT28RS, or have a custom exhaust manifold fabricated that will house a stronger aftermarket external wastegate.