Seems like you should be alright. As long as that piping fits your car, should be fine.

 

Yes its perfectly fine just the filter is horrible and doesnt do its job...

 

I wouldn't get it. It's around .25" too big. Look for one with 2.5" diameter piping.

Make sure you definitely get a nice filter. Look into AEM dryflow.

 

What's the big deal if it is .25" to big?

 

It's not a "big deal," but if you can get one the same size as your throttle body, then why not?

 

Alright, thank you I appreciate it.

 

Ok I'm going to explain this to you. If you get a 2.5 inch pipe, with a 4inch outlet, your going to have a LOUD, Rice filled, backpressure filled exhaust.
You want all of your piping on your car to match. From your intake to your throttle body, to your exhaust. It all needs to be one size to be most efficient. And step away from the fart cans. You don't need anything that big on your civic. If you decide to run 2.5' - keep the inlet and outlet of your muffler the same as the pipe. I seriously recommend moving the mounting location of the muffler. Back when I had my hatch, I moved it to the middle of the car, and ran the pipe all the way out the rear. Not only did it look clean and stock, but it had a nice tone to it. Not too loud, and was a down low tone. You'll get a lot more respect from everyone in the car world if you keep that beast quite and looking near stock.

 

Alright, thanks a lot man

 

And don't get this.

http://www.speedzonemotorsports.com/...productid=2370

 

I'm going to have to disagree on this one. It's more of the canister style that will determine your sound, not so much the outlet size (although it does matter some). WS2's have a ~3.5" outlet and they aren't loud and rice filled.