i got my powercore race cat from landspeed racing. it's really no more than a baffled straight through test pipe(baffles around the outer edge but 100% hollow down the center). stainless steel, and already has 2 bungs for o2 placement. it comes with gaskets, hardware, and bolt to plug one of the bungs. fit like a glove. i paid $150, and to me it was worth every penny. throttle response was quicker and made a noticeable difference to me. car pulls nicer. but the exhaust did get louder.