Maddog is right on. I can't add to it except for when I did this I did notice that when I drove in to the dealer ship for my 1st free oil change the mechanics like how she sounded and I had alot of compliments.
Oh and it's louder and sounds better too :P BEWARE, it does come with a free mod, a really heavy right shoe.
Raptor Step & Bed Rails | K&N | BakFlip HD | Halo Proj. LIghts | Recon Brake Lights | DDM HIDs | Big Rig Lights | Night Raider Taillight Bar | Volant CAI | Magnaflow 18 | MGP Caliper Covers | Lower Billet Grill | 20% Tint | Blistein 5100 @ 2.8 | 34" Tires | Dipped Chrome