Certified...I can help you get your boost gauge reading to work on your DD. This is what I did on mine....I'm with you on the EGT concerns....I've thought about purchasing another factory EGT probe and extending the wires to plug into one of the plugs under the truck and see if that signal would work. But back to the boost gauge....you need to install the rescale signal calculator from the DD update tool.....you may have done this when you first got the unit, Spartan has instructions on their website under FAQ - Tech Support on how to update the DD for the 6.7. Follow these instructions and select everything that is listed on the Spartan FAQ and the RESCALE SIGNAL CALCULATOR...it is toward the top of the list. Once updated, from gauge screen select exit...select setup...select devices....select manager.....You'll see:
a- Generic OBD2 (on J1962)
b-
c-
d-
e-
etc....
Select "b-" & then select "Add Device".
Scroll right or left until you see "ECU", select "Ford UDS", & then select "Install".
From the "Port To Use" screen, select "J1962", then select "OK".
When you see "Device Added Successfully", select "OK".
Next:
Select "c-" & then select "Add Device".
Scroll right or left until you see Rescale Signal Calculator, select, & then select "Install".
Make sure you select find signals again....next select parameters....scroll right or left until you find the calculator and select to setup. Once in setup....set input signal from "FORD UDS" as Manifold Absolute Pressure...set multiplier signal as "Constant Multiplier from Rescale Signal Calculator"....set multiplier sign at "1"....set constant multiplier at "12.31".....set offset signal as "Constant Offset from Rescale Signal Calculator"....set constant offset at "barameteric pressure-1.044 value"....set offset sign at "-1"....remaining options are personal preference...naming the signal...amount of places read after decimal.
Constant offset value example: (barameteric pressure-1.044)...I'm at 1100ft so my barameteric pressure is 14.2 hence (14.2-1.044=13.156)...I rounded to 13.16. This calculation is just about dead on.
In the gauge menu, make sure to select the calculated value for your gauge reading.
Hopefully this helps anyone who is wanting to setup a BOOST gauge on their DD.