I am planning on buying MBRP pro or the xp 4" turbo back system. I have a 2004 ford excursion 6.0 with a brute force cold air intake other than that i am all stock. My question is that I see you use factory cat now does that system come with the fittings to reduce back to the inlet and outlet size. I see on some you can get a test pipe for that spot. With my truck what should i do? What will it do to my truck if I don't run a cat?

 

PM on the way.

Kenny
352-636-0812