Exhaust size

What is the stock exhaust pipe size for my car, and why don't i know this WTF?
I found a """high-flow""" cat, it says 2.25" for inlet and 2.5" for outlet ; 92-00 civic and 94+ teg.
Yep, it's one of those ebay ones
$4.99
But after i decide that probly isn't a good idea, i will still wanna know the correct size.
Thanks in advance B)

 

I'm pretty sure 1.5 for a stock dx,lx,ex.

and for your b16 just get a test pipe.

 

Deth has always been my hero

But im also thinking for $4.99 there can't be too much cat left in there B)