Incomplete regen and turbo delay cm871

[JimT]

If that is the original DOC than it's likely no longer good. It can be perfectly clean and flow fine, but if it can't oxidize the exhaust/fuel properly then you'll never get a proper regen. The metal coating on the DOC that does this will wear away over time and become less and less effective.

I would start with an EGR tuneup, however I suspect the DOC might be the culprit. During a forced regen the DOC might still perform adequately, under that highly controlled environment. Also, when starting with a clean DPF the forced regen is mainly to allow the system to calibrate as there shouldn't be anything to actually clean out.