2007 Gmc Topkick

[STUGAN]

I have 2 2007 Topkicks that I use in the oilpatch. We work on drilling locations anywhere from 4-24 hours at a time. The problem I have is that with the PTO engaged and the trucks reved up the DPF light still comes on and the warning chime runs constantly. This usually starts after about 2-3 hours of running time. This has happened since new. It makes it impossible to try to sleep in the back seat when the other guy is running pipe. How do I fix this issue?

[Nytemare]

 

Sorry man...had to...I have little experience on diesels.