You should call Linear Logic and ask them. Scanguage may not be reading the Paccar correctly. They have a patch for it. (480)656-3842 that is their number
Called Scangauge, The young lady that answered said it probably hasn't been in the truck long enough to fully calibrate everything, to call back if I continue having the code pop up. Said they were having problems with the paccars in earlier versions of the software on the scangauge d, but all of that has been fixed in this new version. So, guess I'll be patient a couple weeks. She did say that code 184 has something to do with the instantaneous mpg and that it was a valid code.