New Cats and O2's... Still giving P0420 code

[manibot]

A few months ago, I replace my cats and O2 sensors with Magnaflows and Denso Sensors. Randomly, a couple of weeks ago I had a misfire code due to a bad no7 plug. Got that fixed. Now I am getting the Catalyst code for bank 1. Did I buy some bad sensors or bad cats? Or is it something else that I could be missing? I reset the code and it still came back. I really don't want to have to buy and put new ones on again... last time I did that while it was snowing...

[0rion]

one way to rule out a sensor is to swap them side to side and see if it starts throwing p0430.

[importhater81]

The misfire on #7 could have damaged the cat on bank 1,especially if that cylinder was dumping raw fuel into the exhaust.