Service Truck down, turbo issues

[Diesel_N_Blood]

Hey guys

Any help would appreciated, by my company and myself.

I have a 2006 F550 for a service truck at work. While we were restoring power in Long Island after sandy the truck would not have proper power, she would not build boost untill about 2700rpm then it would over boost and seemed like it was causing to much exhaust backpressure because the rpms would almost start to drop and it would stop pulling. The truck weighs close to 17000lbs loaded with tools and equipment. I have an AE and no codes are showing up. I can cycle the turbo vanes. I was receiving a MAP sensor malfuntion code about a month before and replaced it. The intake was cleaned at the end of August when egr delete, 8 new injectors and new reman turbo were installed. I have checked the map and map hose/ connection. Both are clean and working.

To add to this problem is it is inttermitent. Some days it will drive fine and others it wont.

Thanks for you help in advance.