im going to replace my o2 sensors, also i would like to punch my cateletic covertor, is it a good idea? i can tell that my truck needs a new one, it smells like its running rich.

if you have an o2 sensor in front and in back, i wouldn't try it.

If you needed a new c/c, you would get a check engine light because of the HO2 sensor behind the c/c. It's purpose is to monitor function of the c/c.