03 6.0 loss of power and fuel milage
 

I have an 03 super duty with a 6.0. It has a 4 inch turbo back straight pipe and SCT flash tuner. It went into limp mode a couple weeks ago. I found that the boot coming off the turbo had blown and replaced it. No fix. I took it to the local ford dealer and the found that the hpop was weak. They replaced it and now the truck has very little power and my fuel mileage is rotten. I burned a quarter tank in 30 miles. I took it back to them and they said every thing checks fine. I'm at a total loss on what's going on. Any help would be greatly appreciated.:argh: