Kooks - 113135002-1/2in. Catted H-Pipe. 2005-2010 Mustang GT 4.6L 3V. Requires Kooks Headers.2-1/2in. x 2-1/2in. OEM Exhaust Catted H-Pipe. Must be used with Kooks Headers. STANDARD RACE CATS NOT FOR USE IN FORCED INDUCTION APPLICATIONSKooks Headers and...