throwing a 0420 code 1998 civic EX
 

So yeah. the light is on.
i have been reading up on it here and there, and some say it is the cat, some say it is just the o2 sensor.

that being said, if it is the cat, if i cut off the cat, and put in a "test" pipe, (no emissions testing where i am from) i would still have the CEL light, but would it hurt/help my fuel economy? or would i have to put in some dummy o2 sensors.


any help would be nice.