ive been having ongoing problems with the dpf in my 08 3500 mega 6.7 engine light come on milage goes down to around 8-10 mpg town i2 hwy been in dealer ,at least 7-8 time loose it for 2-3 days each time .has 39000 miles on it .also steering box has been leaking for going on 2 yrs my dealer ordered a new box but tell me its on national back order and 1100 other people are waiting too.anyone else in this situation r ami just that lucky?

 

I'd stay ontop of them regarding your steering box. Common problem.
As for your DPF, is your truck in Regen mode? I would suspect you could have a leaking injector or a possible bad/dirty glow plug.

I moved this to Diesel for better assistance with your question/consern.

 

Are you getting any overhead message, dpf full messages? Is the truck getting a lot of idle time or short trips where it doesn't get warmed up?

These trucks need to be run with a load or else on the road to keep the dpf cleaned out. I would also suggest running with the exhaust brake on as much as you can, seems to help keep the turbo operating better.

The newer software has helped a lot from what it was when they first came out. I would definitely keep after the dealer on the dpf problem even take it to another dealer if you have to.

Also, no glow plugs on the cummins.

Jeff.