a cat back exhaust is any exhaust that bolts on after the cat. full piping and everything. gains from an exhaust are minimal. 2-5 hp if you're lucky.
you made me sounds stupid
haha but nvm i've learn something new
until today i thaught that the exhaust system on the EF civic (with 2 90 degrees bend type) is something called the cat back exhaust system
haha what a shame
ThaNkzZzZ for correcting me
but are you sure that exhaust system will only contribute 2-5 bhp ? ? I think it should improve much more then that