Tyler.. On the APPS.. you can use your ADR.. Just look at your throttle position, make sure you are getting 100%.. On the MAP.. with out a scanner you can still look at the voltages by back probing the sensor connectors.. I use little sewing T Pins.. I don't poke the wires.. just slide it down between the wire seal and the wire, so it make contact with the pin internally.. I have lost the list of voltages.. as far was when you are at Xpsi what the voltage should be.. but if the voltage is changing, at least its getting from the sensor, to the box, and leaving to the ECM.. with the scanner, you would get a better check, because you will see exactly what the ECM is seeing. The T-pin trick is a good quick field check..
How does the boost value read on the ADR?? Mine still has a bounce or spike.. every few seconds it spikes up about 8psi and back.. (but my monitor is on some old software..)
How many times have you changed that MAP..
You have something little holding that truck back... You'll get it... Good Luck,
Bryan