P0430 is bank 2 sensor 2. To diagnose, do the easiest first: check for exhaust leaks and address as necessary. If problem remains, swap B2S2 and B1S2, clear the code and see if P0420 or something else appears. If the DTC follows the sensor (e.g. P0430 goes away, but P0420 appears after you switch the sensors), that’s your issue.

If the O2S1Eq and O2S2Eq is the equivalence ratio (lambda), the target value is 1.00. A value of 1.00 is equates to a stoichiometric mixture of air and fuel. In other words, exactly enough air is provided to burn all the fuel present in the combustion chamber. However, you will hardly ever see lambda value of 1.00 when at higher RPM. In these conditions, fuel is supplied at such a rate that it cannot all be burned, instead the unburned fuel is compressed and evaporates which cools the combustion chamber. It may sound odd, but this is by design and provides for more efficiency.

If you capture a log of the following PIDs/sensors you will have a better chance of narrowing your search. You can also upload the log(s) to the Torque webviewer.
It is possible that not all will be available:
– RPM
– engine/coolant temp
– all O2 PIDs
– volumetric efficiency
– short term fuel trim bank 1
– short term fuel trim bank 2
– long term fuel trim bank 1
– long term fuel trim bank 1
– air-fuel ratio commanded
– air-fuel ratio measured
– air-fuel/equivalence ratio (lambda)
– catalyst/exhaust temp bank 1
– catalyst/exhaust temp bank 2
– MAF rate