my borla is actually a cat back.....wat is a resonator???.....wat if i put a high flow catalytic converter???

I own a base 05 matrix with these mods : borla exhaust, aem cai, aem pulley, eibach springs. I want to straight pipe it and remove all catalytic converters to have the loudest sound possible. Can anyone help me out as to how i would go about doing this?..pictures would be great