i have an 06 cummins and was wondering what i should do in terms of exhaust i don't really want to go any bigger then a 4in and i know that is what is on the truck already so i was thinking of just getting a muffler and cat delete but was wondering sice i plan on getting a programmer soon so would my egt's be ok with the stock exhaust straight piped or would i be better off getting a new 4in turbo back exhaust

 

4" is fine, thats what i have on my 12 valve

 

I have a 2004.5 with 4in stock exhaust NOW. You can just get a Cat delete pipe, muffler delete pipe or replace the muffler with a free flow muffler.. I have a muffler delete now with my resonator still on the truck. Sounds okay. But I miss the MBRP turbo back exhaust... But that was worthless for me Since my truck is stock with a Bully dog adding power..
If your getting anything it really needs to be Gauges before you buy any exhaust or programmers. Unless the programmer has it included...

Your EGT will not be any lower then they are now with a $580 turbo back exhaust. Been their done that if your not seeing over 600 hp don't bother getting a full exhaust system just get the delete pipes

I also have to change my sig I dont have the MBRP exhaust system on my truck anymore..

 

Just get the cat and muffler delete pipes

 

thanks for the help and i am getting gauges for the truck when i order the programmer but the programmer wont be probably a couple months just want to get my intake and exhaust first