Hi and welcome to the forum.
If you remove the exhaust system and do nothing with the two sensors in the DPF. The ECM will think the DPF is plugged and you will go into limp mode and inform you that the catalysis is full. You need to add a programmer to the truck's ECM such as a Smarty or like an H&S mini max, to keep it out of limp mode. These over wright the ECM program with a different program to resolve the emission delete issues. They do leave footprint in the ECM.
I believe the MP-8 is just a pressure box that can be stack with a Smarty or H&S components or stand alone, but you can not change the exhaust system with just the MP-8.
Jim W