Engine Catback vs. Stock

Catback vs. Stock

Hey whats up guys. This forum seems to be moving a little slower than it did before it went down for a while, but i thought id ask the question anyways. So ive finally realized that my generic-ass welded on muffler is doing me no good other than drowning out the music and what seems to be slowing my car down. ive heard from some mechanics that the stock muffler in my I-4 creates back-pressure which essentially makes my car go faster. now, im thinkning of buying and OEM muffler from http://www.autopartsauthority.com/m...olla~parts.html
which seems like a pretty good deal considering the dealership is asking for like 500 installed. my question is, if i got a cat-back exhaust system with 2-2.5" piping, would i see the same gains as i would with my stock muffler, or would i get even more than that?

i you buy the alphawerks cat back consider the noise your complaining louder. you loose something to gain something. man...500 bucks is stupd crazy for oem shit! pay 600 on the alpha works and install it your self..exhaust systems are easy!

if you get a catback with an aftermarket muffler, yes you'll feel some gain, not much, but some

if you're using stock pipe, you're not gaining shit
if you're using catback with stock muffler, you wont gain shit

ok, i dont think you read my post correctly. I didnt gain anything from the noise, i lost something. I can get a stock muffler for 139. I understand the catback will be louder, but will I actually get any gains from it UNLIKE my generic aftermarket muffler.

The Alphawerks exhaust is cool but currently I'm having a problem with my and my engine running super rich with the engine light on because of it.