Downpipe Kit with 300CPSI Racing catalyst converter for Subaru WRX STI 2007-2018made out of high quality stainless steel 1.4301 (SS304)complete Ø 76mm (3)high quality 300CPSI Euro6 standard racing metal catalyst converter100% perfect fit, plug and playless thermal load on the turbochargermore power by reducing back pressuresignificantly more torqueoptional with Ø76mm (3) decat-pipe
