My friend has an extra cat for his rx8, he wants to sell it to me for 50 bucks and hollow it out (bust out the honey comb) to make it basically a midpipe.

How well will this work compared to a mid pipe?
Will I need to tune my car?

Is it even worth the trouble?

It will work fine, you'll get a CEL for 'low cat activity', which you can ignore.

It actually sounds good, since the original resonator and the cat chamber are still in place.

The only downside over an aftermarket test-pipe is the weight - the stocker is thick solid metal, and weighs about 15 lbs more. But for sound and power, it can't be beat.

S

Im assuming you dont care about warranty........ I have one and my warranty is GGOOOONNNNEEEE....... I waited til after 60K though :)

Well I'll keep my stock cat for inspection and bringing it into warranty work.
thanks guys

yea, as long as you keep your own cat your good.