Wow this has to be one of the most demented and ignorant threads I've ever seen on PW. Not only is bad advice being doled out, it's also being gobbled up and repeated eagerly by more people. Remind me to order a shipment of muffler bearings and blinker fluid for you guys. It will silence the phat phat sound from your cat-less exhaust 
Seriously though, the fuel sold in PK is NOT leaded. If it was, your high compression JDM imports wouldn't be knocking, and you would be complaining about dead O2 sensors. Your car's engine, it's ECU and exhaust are designed to operate as a complete SYSTEM. By removing the catalytic converter you are introducing inefficiencies into the operation of this system. Not to mention, the device converts exhaust emissions into less harmful gases. Before you decide that the imaginary gain in power and economy is worth destroying the air we breathe, remind yourselves that one day your grand kids who inherit this polluted planet will look back and think their ancestors were the idiots who ruined the environment to save a few bucks on petrol.
