I know I have seen this topic on a couple of other threads but I don't have a definitive answer yet. I am just wondering what is the stock diameter size of my 2004 Mazda 3 s. I am looking to do an axle-back muffler replacement and hoping that I can find some that will be a better fit. Any insight will help, thanks!

 

IIRC the stock is 2.5 inch. Mazdaspeed is 3 inch. I had a mazdaspeed exhaust put on my 2006 mazda3 hatch and its pretty dang loud.

 

actually it looks a little smaller than that

 

Thank you! Does anybody have details and specs for the '10 CX 9 (3.7 litre) stock exhaust pipes? I need to replace my mufflers (again) and a looking to downgrade to a more stock-like option. I have a muffler shop to weld, etc, but I need to match the inlet diameter to the resonator-back pipe.

Thanks mucho!