I got a 2016 f550 fully deleted egr,block off plates , tuned . We recently changed transmission installed new turbo and egr block off plates and now we are getting a over boost code p0234. We replaced turbo again assuming that was the issue because it was a rebuilt turbo from Ford so we installed a new one problem still exist checked all up pipes checked for boost leaks on charge pipes replaced boost pressure sensor, mass air flow, EBP Sensor checked wiring to turbo solenoid everything checks out good still having the over boost issue . Whenever I get the code it derates the truck and blows a bunch of black smoke takes forever to build boost . You clear the code and the truck drives normal until the code is tripped again . One thing I have notice is if I power brake the truck it starts to pressurize the turbo coolant reservoir and spits coolant out the over flow tube maybe a bad cac?? Just curious if any has had this issue and resolved it. 2016 f550 6.7 deleted,100hp tune ,egr block off, cp4 disaster prevention kit .