My problem is that most places won't remove a cat. Here in Indiana, we do not have emissions testing and since the car is registered and titled in Indiana, there cannot be a citation issued in another state for lack of emissions equipment. I only want a slightly louder tone than stock, which is why I am keeping the stock mufflers. I'd like to gut the cats, remove the resonator, and then leave the mufflers alone. Tone should increase a bit. Would fuel economy increase at all or decrease? I'm getting just under 20 MPG, but I still need to do a tune up and put my OEM rims back on for the winter/school year (Commuting).