Smoke coming from under the cab driver side during regen.

My truck did the exact same thing during regen. It was my exhaust flex pipe, the clamp had become loose and I replaced the whole pipe and clamp and the problem was solved.

 

I'd suspect because of less exhaust backpressure. The DOC, DPF and SCR are designed to flow relatively freely but there's still going to be some backpressure from them.

 

Exhaust leaks. Fix it before it derates on you. I had exhaust leak and dpf wasn't getting hot enough to complete regen so it derated on me in the middle of nowhere

 

Ha e same situation
See your clamps . Most is coming from this region . At the buttom of the clamp you can see the pressure is pushing the smoke . That's befor dpf filt. Those who saying is def injector may want to check test it woth the software or at least the voltmeter. The regen Clea Ning the dpf is doing fine , so I doubt it is the dpf filter .. just a lose clamp since is a lot of pressure to burn the soot level

 

Check the flex pipe downstream from the turbo. They are prone to getting holes or just splitting.

 

Needs a flex pipe!