Hi Damon: I used the CAT E.T. tonite on a 2000 GMC 7500 w/3126. Used a Dell laptop, we have the CAT 171-4400 communication adapter 2 group. To hook up successfully to our unit, I used Cat Cable 7x-1714,com adapter 207-6854, CAT data link 171-4401 adapter, Cat ... Login to read more.