PO 430 Code Catalyst Efficiency

Just recently replaced an o2 sensor and check engine light was off. That was 6 months ago. Today Code 430 came up with obd reader stating a catalyst efficiency bank 2. Does anyone know if this is the catalytic converter going bad on bank 2? Any advice is appreciated.

take the vehicle to a dealer and have the pcm reprogrammed - there is an update for this problem that fixes the problem most of the time - otherwise if the cat is going bad it is covered 8/80

Thanks for reply. You mentioned the cat would be covered 8/80. What does that mean? even on a 1998 vehicle? Thanks again for any add'l info.