ecm completed regens

[JimT]

could be a lot of things. sensors bad or clogged, DOC washed out/no good, bad or stuck EGR valve, exhaust leak, bad,clogged or leaking dpf doser injector, DPF full of ash... and the list goes on...

Would need a lot more info to try to narrow it down. Truck and engine info/stats (year, mileage, regen history from insite, oil consumption/blowby, been inframed? operating coditions, driving style, etc...) EGR tuneup done recently?

A wild guess would be that DPF temps never get high enough to completely clean out the DPF. Maybe driving down the road it trys to active regen and you get a lot of white/blue smoke out the exhaust with a heavy fuel smell? Could be any of the items listed above, however based on the age of a 2250 engine I'd say the DOC probably needs to be replaced.

Could also be burning a lot of oil which is clogging up the DPF while it trys to regen. The oil coats the DOC and DPF quickly, reducing the effectiveness of the DOC and when it does burn off it leaves behind ash which will clog up the DPF. Add that to an aged DOC that probably isn't oxidizing very well and you get endless regen cycles, eventual derates and clogged up DPF.