I have the complete catalytic converter out of my car since we had to madify the new header flang from the vtec enigne to fit the h23 cat, but i was wondering if anyone has "hollowed out" their cats? If so did you notice any rattling or excessive exhaust noise? Or would it be good for backpressure? I know people do this kinda stuff to trucks and SUVS but havent heard much on the prelude boards? If anyone has any thoughts leave a post. TY

 

I believe that it is not worth the bother to do so. CELs, and smog. you save like 2 hp.

 

i live in AL so no smog and its obd-1 so no way to throw a CEL since theres no O2 sensor after the cat? but u think it would make HP?

 

bump

 

I hollowed out mine and no smog or cel. I didn't notice to much difference maybe in throttle response. You can hear air rush through the cat it sounds kind of cool.

 

that's because most people just buy a test pipe...

 

bump

 

Just make a test pipe. Alot easier and less time consumming!

 

When I bought my hi-flow cat, I hollowed out my stock one just to see for myself what it was all about. I hated it! No, I didn't throw a CEL, I just hated the way that it sounded. I pulled right back into the garage and threw my Cat-Co highflow in. Ahh...much better.

 

If anything just buy a test pipe, but you will get that raspy sound after you do it.

 

i guess ill jsut leave it be right now and when i buy a cat back ill buy a hi flow too, but already spent more money than i have soo trying not to spend anymore

 

the story of all of out lives

 

mine rattled bad so i bought a piece of 18 inch pipe and put it through it.