Lilhalls

Thank you for the advice to try it on the rear Ox sensor. This is not a turbo car so where can I find the bank 1 sensor #2 under the car?  I will use the Dorman 42009 and drill out one of them with 1/2" drill do I use two of them togather or is one enough? 

I have a 2011 Ford Edge with a P0420 cat system efficiency below threshold bank 1code. I don't have the money for a new Cat so I noticed on youtube to try a non fouler. I put it in on the back side of the engine near the firewall. Now I get the P0420 and P0133 o2 sensor slow response bank 1 sensor 1. Do you think I should have installed the nonfouler under the car by the Cat? Any help is appreciated as I am desperate at this point.