Invidia Down Pipe/J Pipe w/300 CPSI Cat - Subaru WRX VA 15-21 (Manual)New for 2024: Revised design with 300CPSI catalytic converter to suit stricter EPA emissions requirements INVIDIA CATTED DOWN PIPE The most restrictive component of the factory exhaust system is the down pipe which begins right after the turbocharger. Invidia Exhausts use a larger pipe diameter and smooth bends allows the turbocharger to exhale exhaust gases with fewer restrictions and turbulence. Because of these reasons, Invidia down pipes make for