To update what the problems are. Injector # 8 failure, DPF 100%, DEF injector failure. The more I think about things the more this problem has been manifesting. I just never drove it enough that the concern got my attention. When I got the truck I averaged 18+ mpg, currently down to 16.4. I'd say the injector failed and everything else got overworked trying to do its job. Good news is that we had the fuel tested and no metal in it. Taking this opportunity to have a disaster kit installed and do the basic bulletproofing. Bad news is that I don't currently have anything else to drive...so, I'm rolling the dice and driving it. As I truly believe this has been an ongoing issue.