HELP, 2013 maxxforce 9 low power/boost

So during a recent a acquisition I ended up with some real junk trash trucks, go figure. Trying to sort through this mess I have a 2013 international 7400 with a maxxforce 9.

This truck has not been taken care of very well, but the labrie side loader body on it is in great shape and the truck isnt horrible so I wanna get it running good.

The truck is just a dog, I know these arent known for their crazy power but this thing is unusable.
Work ive done as maintenance
-crank case breather
-dpf and doc were cleaned
-egr valve was changed, stuck open
-boost tubes and solenoid
-intake manifold pressure and temperature sensors
The basics, the truck has no boost about 18psi, the exhaust back pressure valve moves with a wrench. The only code is tc1top out of range low I believe.
One more note is my exhaust back pressure reading is not constant. Sometimes it just comes up with "error"

Any help is appreciated, not really sure where to go now.

 

So, I pulled the intake apart the grid was a little crappy but not plugged by any means. I replaced it anyway, pulled housings off turbos, clean as can be. Is there anywhere else you can point towards? I dont wanna really throw money at this thing not being sure. As you know the international diagnostic software isnt the best lol These things are not my forte. Thank you for the help.