Which one is the downstream sensor? Before or after the converter?

Question

I have the error code P2096 and P420
I already replaced the sensor after the converter, but the error is
came back

Answer 1

P2096 Downstream fuel trim lean Bank 1

P0420 Catalytic below efficiency Bank 1

The downstream 02 sensor are after the catalytic convertor, These are listed as Sensor 2. For P2096 if there is any exhaust leak prior to the catalytic convertor this would set the code,

​ Here a P0420 catalytic below efficiency , for a good catalytic convertor it downstream 02 sensor which monitor the catalytic convertor would read above .650 mlvolts, here it is below the required amount , this is a failed catalytic convertor