As it was stated, it depends on your location. For example, I grew up in Adams County where there is a visual check "is there a cat...yep...pass". It could be gutted and not matter. Moved down the road into York County and they actually test for emissions. Whatever the computer tells them is the result, not sure if there is even a visual check.

And not to be that guy as this is just my opinion, but anyone that stumbles across this should strongly consider running a high flow cat. Outside of cost there is really no reason not too. It is much better for the environment and has little to no effect on performance. If nothing else, you are sucking in less fumes...unless you are into that sort of thing