On a 00 civic ex SOHC V-TEC can you hollow out the catalitic even though one of the o2 sensors is mounted on it?

The reason I ask is because i think mine is clogged and I would rather hollow it then buy a new one, but i don't want to upset the A/F mixture.I also have a CAI and a DC Sport 4-2-1 Header with a stock ex muffler,thanks

 

Well, you can do anything you want. You might throw a CEL, you might not. Its not gonna throw your A/F ratio off that much at all...

 

and what is a CEL?

 

Check Engine Light.