::) Unless you live in an anarchal state (Somalia for example) it's generally a governmental regulation that says you have to have your exhaust systems intact. It's a federal law in the USA and I know Canada says the same thing.
That said, don't expect much with or without the cat unless your system is so crappy now that the cat and muffler are clogged right up. I noticed a little bit of an improvement when I put my high flow cat and straight through muffler on with the Calmini setup. Is it there? Yep. Is it the same as a blower or huffer? No.
Also, do some research. A lot of testing recently has shown that gutting or removing cats compaired to running a modern, high flowing cat is basically pointless and ineffective. Some tests show a very minor gain, others statistically no difference, and some show a loss of power. For what it gets you the chance at getting that federal ticket from the officer isn't worth it in my opinion. Yes, I've seen that ticket issued and beleive me it ain't cheap.
1. I am operating under the understanding that it is illegal to modify existing emissions control equipment. However, I have been told that replacement components (i.e.: A aftermarket new exhaust system) does not
have to make your vehicle meet the same emission standards as the existing system. I'm assuming that if your vehicle does not meet emissions standards, its illegal, but because we have no emissions testing here in Alberta for light passenger vehicles...who the hell is going know? Besides the old converter is shot anyway so what good is it doing anyway?
Try phoning a local police station with questions about Highway Safety Traffic Act...Either the cop doesn't have a clue, or he thinks he knows what he's talking about, actually doesn't, and misapplies the law. Once I got a ticket for my fog lamps, they weren't even on and they were factory equipment. ÂÂ

2. The chances of me getting a ticket for running an exhuast system without a cat. are pretty much non-existant. The police here either are: 1. So busy there is no way they even have the time to check. 2. No nothing about vehicles (see above).
3. The only reason why I don't want to run a cat. is because mine is rotten out and I don't feel like spending money (lots of $$$) on a replacement. I don't think I'm going to get a massive HP boost, but I am curious how much backpressure one adds.