I took mine off last year and I get better gas mileage that is for sure. Its the air flow is all it will block it a bit and give you bad gas mileage. I wouldnt do it if you have to have your car/truck/SUV IM'ed. The reason being is that you will never pass EVER without it on. I know its a pain cause when the suckers go out it can cost you a bunch if you have it done got you. I do all my own work with the help of my husband. So if its out go and find an after market one that will help you out with the cost but most times shops will do it cheap. For me to put mine back on it will cost me $200 at a shop for a whole new set of pipes and cat. For me to do it myself depending on where I get the cat from. It goes anywhere from $60-$150. Oh the insides of the cat can be recycled and it will help with costs so if you have it taken out ask for that part back and take it down and get your cash back on the insides. Every little bit helps out right.
