Help with p0420 code

[OGsohcHondaLOVE]

I have had my truck for about a year and a half now. First mods I did were the Superchips Vivid, cai , and full 3" custom tig welded stainless with a custom y pipe. The code came on right after the exhaust install. I've replaced both secondary o2 sensors and no luck. It is for bank 2 so I did some defaults to space the o2 out a bit. I feel like I'm stuck. My truck get horrible mileage which isn't supposed to have to do with a secondary o2. It also seems like it's not accepting my tunes because of the cel . I have my mds turned off in the programmer but I still feel it engage.

 

[OGsohcHondaLOVE]

It is a P0430 also not the other code

 

[Gecko]

Check and make sure there isn't an exhaust leak right around the o2 ****. If there is fix that and it should take care of your problem.

 

[OGsohcHondaLOVE]

There isn't an exhaust leak by the ****

 

[chefred112]

still have your cats? if it bogs maybe a clogged cat?