P0420 come back

Hello dears

First of all I want to say thank you for the halp I get in this forum. ❤️

I have Prius 2008 262000 km.
I hed p420 code and after a lot of research and asking in a gerege shop I replaced the catalytic converter . For 700km the it was good and also the gas mileage improved from 5.5L/km to 5.3 L/km and today the code come back!!

Important information

1. After I changed the cat' I cleaned the maf sensor, there's any possibility that I have create a damage to the sensor and it's affect the cat'?

2. The car are burning oil, but lass then 1L to 1000km.

Maybe I was need to change the oxygen sensor??
What oxygen sensor I need I saw to many of them and didn't get which one of them o need.

I will be very happy for any help
Thank you