I have an aftermarket shiny and loud jdm backbox on my ej9 but it's welded on to the Bpipe. I want a quiet one. Would an oem EK9 catback system bolt on without any mods?
you need an adjustable jdm decat where the collector is at 2.25" and the at the b pipe it's 2.5" IIRC. the sizing of exhausts still sometimes confuses me. but i think you could change the flanges to make them fit? not too sure, just get a japspeed manifold with a 2.5" collector