Smallen up your signature picture, please! LOL
As for the downpipe, you'll need to PARTIALLY lift the cab, cut it, or pull the trans.
I believe you NEED to run the EGT sensors, I may be wrong on the Black Maxx. The factory calibration LOOKS for EGT 13 -- see the announcement in the Performance Parts section. It bases engine overtemp/shutdown on EGT13 -- it's a failsafe.
Program your truck, and leave EGT13 (the last one after the DPF) unplugged. Start the truck, let it run for a couple minutes. Shut it off. Re-start it. Do this a couple times. If it continues to start, you don't need that sensor. If it won't crank/start -- you'll need to wait an hour before it'll start again or follow the directions in the aforementioned thread -- if this is the case you NEED to leave those sensors plugged in, and you might as well just put the sensors in the pipe.
Hope this helps.