Smoke from my exhaust ~~~{{{{{{{

[Waterloo]

How much black smoke? Is it quite a bit like one of these kids rolling coal in their pick ups or just a small amount? If it is just a small amount, and you have soot collecting around your exhaust, I had this same issue on my 871, it was a cracked DPF filter. I rid myself of the mandate, as I did not have $7300 at the time to replace the DPF and DOC filters. I then did the in frame and never looked back.

Also, I did all of the above tests others are suggesting, other than the injector leak down. It was my DPF/DOC cans. My injectors were fine. We could tell that as the spray patterns on the pistons were near perfect at the time of the in frame. The truck had roughly 800,000 mile on her at the in frame, and these were the original injectors. I replaced all of them with new injectors, not remans, but new. Motor runs fine. My issue was a bad head, that was also replaced with a new OEM head, not a reman.

Stay away from Lucas and rid yourself of the mandte.

If it is quite a bit of smoke, the first thing I would do is remove and inspect the EGR valve, along with an EGR tuneup. But, it still sounds like those DPF/DOC cans are toast.