as topic stated, please advice

 

don't get bigger cat back piping when you just buy a muffler

 

A muffler is what you see when standing behind the car, just the cylindrical shaped piece with the exhaust tip coming off of it. A catback exhaust is the exhaust piping from the catalytic converter back, including the muffler and sometimes a resonator.

 

that's one of the different. So what's the difference in performance?

 

the piping you get with a cat-back usually has less bends, made to better specs and is biggger in diameter for increased flow. it also matches the muffler so you get the most out of it.

 

flow

 

Muffler = Rice, mainly only for looks and sound
Catback = For power, looks, and sound

Get a catback setup, or get a muffler and have a shop custom make a mandrel bent exhaust setup for you that is designed for your flow needs

 

don't forget that catbacks will usually have mandrel bent piping as opposed the the crush bent pipes from the factory. better flow...

 

If you intend to have a shop make the cat back piping for you keep in mind that very very very few shops actually have a mandrel pipe bender to work with and they'll be crush bending the piping. If you are cheap then go ahead and do whatever you gotta do but if you take pride in your car and plan to keep it for awhile and make other mods to it then save until you get enough for a cat-back exhaust. If you want to get a header and/or high flow cat later it would be a waste of money without a good cat-back setup.