So, I just purchased a 2011 3500 Cummins. I have owned 4 5.9's, but this is my first 6.7. What all is required to straight pipe the truck? Where I live, there are no state inspections, nor does anyone really care how loud or environmentally friendly your truck is. Do I have to delete anything, or is it like a 5.9. Just cut the muffler out, and replace with straight pipe?

 

Were you planning on leaving the DPF and Cat in place and only remove the muffler? If so, then cut the muffler and add a straight pipe, but you are not really gaining anything except more sound.

 

Come to find out, it's already been deleted. Everything is already out, except for the muffler. There's no tuner in the truck, so I'm assuming it has been programmed. Everybody is telling me to put EFI Live on it, so I can at least know what it's set at. I've never had the EFI. Had Bully Dog on my 05, and had a lot of issues with it. Had a Hypermax on my 07, and it was great. I'm not looking to smoke the tires and tear it up. I'd just like it to sound good and increase mpg. Any advice in regards to EFI, or other programs/tuners?