Well there you go.
Just gut your cat out and your set, instant hi flo.

If ya bash out the insides of a cat it reduces power cause then the exhaust isn't as direct as before. I normally go a good brand used one or a custom made one. The one I have on my gt is a custom made one. looks a little worse then a stainless one but can't see past the turbo so it looks pretty alright

at the moment it has no cat in it. But when i took out the cat it started to use more fuel so i unplugged the sensor on the exhaust and it went back to normal but it still ran the same, just louder higher up the rev range