ummm no its just over 2.0" on the collector on my Megan header, dunno if your friend is blind or what..
Their catbacks may look decent on other cars, but just didnt look good on the lude..
They aren't a knock-off brand where are you getting this from!?!?! Some dumb **** thought MUGEN and MEGAN were "so close" that he started spreading this.. its not a knock off brand at all..
anyways, I am welding a muffler, not sure which one yet, something quiet and stock looking, to my Megan catback piping

great quality imo..
It's 2.5" OD but 2.36ish" ID, I measured it myself.