This cat delete down pipe eliminates the catalytic converter for maximum exhaust flow.This high performance race pipe is constructed out of lightweight TIG welded 4 in. stainless steel. 100 percent TIG welded by certified craftsman for race proven strength and durability. TIG welding provides the strongest welds reducing stress cracks. A unique 4 in. tapered design is used to increase exhaust velocity and increase usable torque. This means more aggressive throttle response and increased passing power. This down pipe uses factory mounting locations for the O2 sensors. All hardware and brackets are included for a hassle free installation. This unit also comes with a lifetime warranty. aFe down pipes are engineered and manufactured in our Corona California manufacturing facility. This is a race only product used solely for competition.