2005 Mitsubishi L200 under powered & overboosting

I put this in the forum as well, hope I'm not going to cause problems putting it here as well.

I recently purchased a second hand 2005 L200 Warrior and shipped it out of the UK to the Caribbean when I live. Trouble is, it arrived here and has some serious turbo issues, and there is no Mitsubishi dealer worth talking about.

With everything all hooked up as it should be the engine is way under powered and the turbo screams as I rev. I notice that the VGT actuator arm pulls in when I start, but doesn't move after that no matter how much I rev. If I unplug the VG control solenoid the screaming stops but it's obviously still under powered, and the VG actuator still pulls in and stays in. I have replaced the VG solenoid, it made no difference.

I figured it may be a dirty earth (since I was told that that solenoid switches to the earth), so I cleaned all of the earth points I could find including the main earths. Still nothing.

I had it scanned and it gave error code 41: "throttle valve solenoid", but I have so far not been able to find out what that error really means, and was actually told by a dealer in Puerto Rico that that truck shouldn't even have a throttle valve solenoid (but I think they are more geared to the US market truck which is way different than the UK/Europe version).

The only other thing odd I am seeing is that the throttle body from the inter-cooler stays open, it never modulates as I rev. When I shut the truck off it closes and then opens up again and stays open. I have cleaned it up with some throttle body cleaner, made no difference.

Anyone have any ideas? I've had the truck here now for almost 10 months and have had no luck getting any closer to a solution.

Afternote: It produces approximatly 35 psi (241 kPa) of boost pressure when it's all hooked up. And I have been told that the normal running pressure should be 190 kPa, so it's way overboosting as well.