Their honeycomb design supercharges air flow and powers up your ride's performance, while still complying with stringent smog restrictions. For California drivers, we have a Grand Prix catalytic converter that passes your state's rigorous air quality standards. Our Grand Prix catalytic converters bolt on with no welding or pipe bending, which means you're on the road in a snap. A 5-year, 50,000-mile warranty ensures you long term performance. Join our legions of customers who stick with us for the best automotive products in the biz!