which is better,, must keep on car,

 

i'm gonna go the route of a high flow cat later.....get a carsound cat off ebay for about $40....don't waste your money on a Random Tech one....it's practically the same from what I've heard. hollowing out will probably sound worse than a high flow cat.

 

i hollowed mine out, its not the best sound at first bt u get use to it, u can hear the exhaust expand in the cat shell and stuff but does make it quite loud with borla and is fun to rev it up at night when peeps are sleepin :-D

 

get the high flow. I went without the cat (OR pipe) and its just loud.. hollowing it will cause air distubance in your exhaust...probably make it raspy
The high flow will be your best bet.

 

cars have gone well in to the 9s with cats, so when I see 13 and 14 second cars gutting their cats, or running no cats, I do this--->

 

its called "didnt have an obscene amout of money to replace my clogged cat"