I have a 96 OB with a CEL on. Ran the codes on the car quite a while back and got the one for the catalytic converter. The car has recent plugs and wires as well as O2 sensors. When the CEL is erased it comes back on after 15 ignition starts. Is this most likely the cats? I have no problem replacing them (about $300 for both at rock auto) but I'd rather not if it could likely be something else.