Premier Auto Exhaust uses high grade OBD II catalytic converters made of 100% stainless steel. These catalysts are made from various precious metals such as platinum, palladium and in some cases even rhodium. The difference between a good converter and a bad converter is the amount of platinum used. Platinum is used as a reduction catalyst and an oxidation catalyst and when you cheap out on these materials the lifetime of the converter is drastically reduced and your converter will start to burn and clog. This in turn damages the rest of the exhaust by allowing it to overheat and will reduce your gas mileage as well. It also directly effects the amount of smoke your car is releasing which is harmful to the environment.