What I can't understand is doing an X-pipe AFTER the cats, which go to ONE resonator or for those of you who remove the resonator/center-muffler, to the one muffler in the rear.

My understanding is that the X-pipe/Y-pipe helps in scavenging, so since there are two cats, wouldn't it be more beneficial to do an X-pipe or Y-Pipe to the dual cats?

Besides if you do an X-pipe after the cats, isn't the flow going to either a single center-muffler (resonator) OR single rear muffler? Plus it's past the first pressure point (CAT) so no real scavenging effect. A must read is here: http://e30m3performance.com/installs/installs-2/exhaust/exh4.htm






:-) neil