catback exhaust? info and worth it?

[Decoy]

Hey,

I just bought a 91 Celica GT-S in almost excellent condition with 156,000km. 5spd of course Now to get it safetied i have to fix a hole on the exhaust piping. The hole is after the catalytic converter. But the guy i'm buying it from said he has a cat back exhaust that he bought and should arrive in a few days and he said he'll sell it to me. Will it benefit me any or should i just stick with the regular? And what does a cat back exactly do?

Thanks

[91 Celica St]

it bolts from your catalytic converter back, it chould add a small amount of hp, you erally wont notice unless you put on headers and a high flow cat tho... i notcied from putting my headers and a cat back on then about a week later i got my straight pipe... and i notceid with just the 2...so yea, get it, you shouldnt spend much more then $250 on it, mine was i think 225 (pacesetter 2-1/4 inch)