NC state law says that you have to have a cat to get it inspected. I assume it is your '89 that you are referring to.. If I am correct, they will do a visual inspection to make sure it is there.
You are better off just replacing it. They are $80 or so(I should know, I have replaced 2 already and I need another one now!)
I found the inspection process online.. pretty interesting!
19A NCAC 03D .0542 EMISSIONS CONTROL
DEVICES
A civil penalty shall be assessed against individuals who instruct or allow a
person to remove, disconnect, tamper with, or render inoperable any emissions
control device equipped by the manufacturer of any motor vehicle as described
in G.S. 20-183.3.
1. These devices include:
(a) Catalytic Converter
(b) Unleaded Gas Restrictor
(c) Air Pump System
(d) EGR Systems
(e) PCV Systems
(f) Thermostatic air cleaner
(g) Evaporative Emission System (includes gas cap and fuel tank
systems)
(h) Oxygen sensor
History Note: Authority G.S. 20-2; 20-39; 20-183.3(9);
Eff. October 1, 1994.
Here is the link I found:
http://www.ncdot.org/DMV/vehicle_se...ionsmanual/download/CR435NCDOTEnforcement.pdf