I bave an 09 volvo with a d16 500HP with about 290000 miles on it. I pull double tankers loaded to 140000lbs. I have had a recurring problem with the regen. The 7th injector has been replaced 3 times the egr has been taken apart and cleaned the dpf as well. And I'm having the same problem again today. It does a regen then another and then I get an active egr code temp value too low as well as 7 inactive value too high. And then it goes to level 3 soot level high engine derate active ats service required. My patience is wearing thin.