I'm trying to help my friends son figure out an issue with his truck.  It's a 2018 Ram 2500 with a 6.7/Auto, it's lifted with I think 37" tires.  He had the truck deleted over a year ago and has EFI live tuning and the knob on the dash to switch tunes.  The truck has about 90k miles on it currently and has  stock turbo/injectors/intake.  He just took a job in Montana and drove straight there, about 14 hours I think he said and had to fight a pretty nasty headwind most of the way.  The next day and every day since when he starts the truck in the morning it idles really rough and makes a lot of black smoke.  It will clear up and smooth out after a little bit and run fine the rest of the day though.  The morning temps have been 25-40 where he's at.   

First thought is injectors. Have them tested for excessive return flow. I just had Thor's injectors sent back for excessive return flow. Possible a bad nozzle maybe?

Would an injector suddenly go bad like that?  He's thinking about having them all replaced since he's nearing 100k anyhow.