Please help solve my puzzle!

[Kenworth2012]

(07-28-2016 )JMBT Wrote:  Thanks for the replies, I really hope that does it for mine too.

Hope the exhaust leak cures your problem. If not, check your NOX sensors. Both inlet and outlet. According to Cummins, The passive regen is based off of time. There is a setting in the ECM that tells it to regen every 36 engine hours. Mine was regening every 5-6 hours. I, too had replaced and cleaned everything in the system. During a forced regen, I noticed the inlet Nox sensor was reading lower than the Outlet Nox sensor. I changed both sensors and now it is doing a regen every 36 hours. Hope this helps.