High flow cat convertor. Is it any better?

I have always wondered about this. Are they any better than a stock version. Do you gain performance? I'm up for a smog test next month and with my luck I will probably need a new one. I have 118,000 on my 96, is it time?

Try it. If it passes smog, you're laughing, and if it really has any advantages over a normal one, maybe it will get you some sound out of the deal, too.

Usually a cat will fail around that kind of mileage, but if yours hasn't yet, I'd say leave it unless they tell you that you have to change it. But who knows, my first cat went on my truck at 30,000 miles or so, and my second shortly after, but my truck's motor has issues...