Check engine light, code P0420

There is an exhaust leak on the car, it is audible driving at 5-10 mph or 65 mph next to a wall.

Check engine light returns P0420. O2 Sensor 1 reads 2.2-2.7V and O2 Sensor 2 fluctuates greatly.

Question: can the exhaust leak causes both O2 sensor to return such results?

Is my O2 sensor faculty? Is my catalytic converter bad?

Thanks.