Yup, and somehow er another, the EGR assists the DPF with regeneration. So if you take one off, yer gonna have to take 'em both off. Many guys did one, or the other and had some pretty bad problemos.
I took the muffler off in an attempt to help get the EGT's down a bit, but it didn't seem to work very well. The ol' muffler is just on there for show on these trucks, IMO. Hell, it isn't even that much louder! :thud: