Detroit diesel 60 series problem

I removed and deleted the EGR system on my 2006 Detroit 60 series. It worked great since. I just had motor rebuilt and went to pick up the truck 2 weeks ago and upon driving it on the highway with 26000 in the box, I noticed that the power was not there and that turbo wasn't spooling up strong til about 1600 rpm. It should spool up around 11 to 1200. Took it back to shop and there it sits. They have tried everything they can think of , a different used turbo and ECM. When we first put it on the computer it showed 3 pounds of boost with the engine off. Horsepower feels low and it was at 500 horse prior to rebuild. Have talked with the shop that did the delete and reprogram, they don't believe that it could have lost programming just from being without batteries for 3 to 4 weeks during rebuild. We may have to take ECM off and send it to the delete shop 3 states away. Or rebuild or replace turbo. According to the rebuild shop everything looks normal but the 3 pounds boost when shut off. I'm losing revenue every day it's down, and I'm pulling what's left of my hair out. What could it be? I've even asked a friend who works for Detroit building new motors and am awaiting a answer from their master mechanic. I'm lost!

 

Yes the ECM was deleted and reprogrammed at the time of the delete. It has worked great and has even lower emissions ever since. We think it may be a injector issue. Everything else ha d checked out good.

 

Yes.