Could anyone help with a cm2250?

[AMR95]

I have a cm2250 bbz cpl 3719 that someone had (d e mandated a few years ago)
Anyway it went into the shop for some repairs (Rod & mains) (front cover leaking at block)
So when it was done when you drive the truck now it will go into active turbo speed derate (it was not doing this before repairs) does any of you smart gentlemen have any input on where to start I am sure the t u n e is whack my only issue is it was not doing this before?