I have been running the 5in turbo back exhaust for 4,000 miles now and have had absolutely no problems whatsoever and some other 6.7 owners on here have said the same. I personally think that the 5in sounds and looks better but to each his own.But what about the loss of back pressure? In the 5.9s you can't go to a 5in unless you are pushing quite a few horses from what I've read.
I did the 4" turbo back exhaust (kept the factory muffler). MPG has increased about 20% on 5 full tanks. Was tempted to to do just the DPF and cat just for ease of install and remove. Give it a try you can always do the down pipe latter.I am considering doint the 4"Dpf delete from BADP. I have a question though. What are the pros and cons of just doing the cat and dpf delete as opposed to doing a complete turbo back 4" exhaust? Any input would be great.