Thank you all, after further investigation by the shop it turned out to be the crank case breather was clogged and wasn't letting the DPF regenerate. Replaced and cleared codes and down the road for the low low price of $850! I State Truck Center in Livingston MT. Good work by them!
My son had one replaced at Cummins in Jacksonville, Fl, under warranty. If I recall correctly, they said it was a $2,600.00 replacement if it wasn't covered.
I would contact these folks... might have an installer in Billings. https://www.dieselspec.com/
This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose. Sold 04 Dynasty to our son after 14 great years. Upgraded with a 08 HR Navigator 45โ...
I'm not sure what you need but, Dales Super Store has several DPF's listed. Maybe you can find what you need and get an idea of the cost. I've never dealt with them.