2001 dodge cummins problems

[dirtymax22K]

This is a friend of mines truck its an 01 2500 qcsb 4x4 and its auto. The truck has 150hp injectors edge comp box and aftermarket air filter, the problem is is that when the truck sits and idles it will hiccup and spit and sputter but not constantly just out of the blue every so often like it has a air leak in the inj line somewhere but im confused on it. We unhooked the comp box thinking it might have a short but to no luck still the same any help would be appreciated thanks koale