Need help my 2000 civic is showing an inefficient cat code and is running badly
 

My 2000 Honda Civic coupe has no power and makes a loud cha cha sound whenever I hit the gas. I had the Cel light read and they said it is throwing a code that the cat converter is not running efficiently. The mechanic said that it was probly clogged but there is no way to check without replacing it and a direct fit Cat converter is not cheap. Any suggestions please? My friends say that I should just get a straight pipe or hollow out the converter, but I'm worried about the O2 censor getting messed up and getting more CEL lights. Whats worse is that I don't even know if the cat converter is whats causing the Civic to run horribly. Help Please.

Definitely do not just hollow out the cat or go with a straight pipe. A cat burns up all the excess fuel from the cylinders so that poisonous gasses do not get out into the air around the car. (ie: into the vents of the person behind you in traffic).

"cha cha" almost sounds like a misfire (and a fun dance). When you press the pedal, it just chug chug chugs away until it gets up to speed. Does the CEL flash at all? Is it a factory computer or has it been modified? What trim level is your car? (DX,EX, etc.)

I have an Ex Coupe and everything is factory.The Cel light just stays on.