Only 1 other post on a P0430 DTC.
As fro what fixes it, good question, that post was some what open ended, and I did not see a real soultion posted.
Here is what is in the service manual on it, Sorry I can't add to it myself, I have no clue what else to say on the topic.
P0430 - Catalyst System Efficiency Below Threshold (Bank 2)
Indicates Bank 2 catalyst system efficiency is below the acceptable threshold.
Use of leaded fuel
High fuel pressure
Damaged exhaust manifold
Damaged catalytic converter
Downstream HO2S wires improperly connected
Damaged exhaust system pipe
Damaged muffler /tailpipe assembly
Retarded spark timing
Compare HO2S upstream and downstream switch rate and amplitude. Under normal closed loop fuel conditions, high efficiency catalysts have oxygen storage which makes the switching frequency of the downstream HO2S very slow and reduces the amplitude of those switches as compared to the upstream HO2S. As catalyst efficiency deteriorates, its ability to store oxygen declines and the downstream HO2S signal begins to switch more rapidly with increase amplitude, approaching the switching rate and amplitude of the upstream HO2S. Once beyond an acceptable limit the DTC is set.
Good luck, and post back what you find fixes it for the next member.