Integrated Engineering X-Pipe ExhaustWHAT IS THE X PIPE? Located after the midpipes and before the catback, IE's X pipe replaces the middle section of factory tubing and the sizeable suitcase center resonator. Upgrading this section removes the massive resonator and ultimately frees up the middle of the exhaust system improving flow and exhaust sound. CROSS SECTION DESIGN IE's X pipe replaces the factory suitcase muffler with straight pipes that retain the center cross section exhaust