I have read on here that an aftermarket header pipe will give me better hp out of my runner..it has a 3.0 engine..it already has an aftermarket muffler will the header make that much of a difference? If so where is the best place to get one? What else can i do to it to give it more pep? I read that a cold air intake doesent do much..is it a waste of money to buy it? Thanks for everyones help with my questions..