hey guys not sure if htis in right spot if not im sorry. im new to the diesel thing. and was looking ar the mbrp systems. ? is do i need 4in or 5in? and if i get a the system with the front pipe back what does it do? take out the cat? if so will it throw any engin codes? and is there anything else that needs to be done if cat is taken out? or should i go just cat back. plans right now is air intake exshust and tune, done road id like to do more but those main thing im looking in to doning frist thanks
Eddie
Eddie