Muffler Size
 

I wanna buy a Magnaflow Performance Muffler but the guy @ CT (they're on special there this week) said I need to get the size of the other tubing and stuff in order to get the right one. Everything is stock so I want to know what size I have to get for my car (93 SI coupe). Thanks in advance.

if its a universal muffler you can always get the installer to use a fitment or adapter to adjust from the size of the original piping to the inlet of the muffler. I think the size of your civic is 1.75"