Some exahaust questions, could someone give me the run down? Options

[tonytutino]

Ok so here's the plan: i would like to get rid of my stock exhaust piping, get a new muffler ( i got some nasty 3A racing one right now), and get a high-flow cat.

1) i want 2.25 piping so should i buy the 2.25 high flow cat? it may seem obvious but i really don't know.
2) we don't have emission laws here, should i get a test pipe instead? (whats the difference)
3) does the inlet of the new muffler need to be 2.25? alot of the ones i'm looking at are 2.5 and i didn't know if they welded some kind of adapter or something on there.

i guess thats it, i'm a newb when it comes to exhaust...

thanks in advance!

[k-weaver]

1. + 3.) you should be fine getting everything 2.25. When I had mine installed I had a 2.25" cat back installed and my exhaust was a 2.25 as well. I watched the guy put it on and he kept going back and forth between his pipe bender and my car. He just kept making the pipe a little bigger on the end so that it would fit over the exhaust. So I know if you get the same size an exhaust shop should be able to do it. If you get it bigger I would assume that they could make it smaller but i'm not sure on this one...

2.) WHERE DO YOU LIVE!!! I wish i didn't have emissions laws, i'm in california and it sux...Anyway is your question regarding weather or not to put a high flow cat on or the resonator? If you take the resonator off your car will be louder. I know cuz this happend to me. The stock one is too small to fit on the 2.25" and I didn't have the funds at the time to buy one so i just left it off. The car is SUPER loud but it tends to be whiney. I like the loud but the whiney noise kinda sux. IMO I would say just take off the cat, if you don't need to pass emission. There will be alot of people to tell you differnt tho...