Diesels don't "run rich" most likely everything is normal. Make sure your air filter is clean though
Don't get me wrong. It's not bad. You wouldn't even notice it if you weren't looking for it. I'm going to start trouble shooting Thursday. I'm going to start by switching to rotella with all fresh filters so the injectors get good oil to them. I see there is a good bit of soot in the intake manifold so I may try cleaning that out as well. Any tips in getting it clean?sounds like everything is normal with your truck except the black smoke unless you're tuned in any way. A stock 6.o should not throw a lick of black smoke.