Bank 2 sensor 2 issues

Have owned and maintained the truck since new. In the process of some repairs (new struts, shocks, sway bar links, valve cover gaskets, driveshaft carrier bearing etc.

My Bank 2 sensor 2 threw a P0430 code awhile back. After a few other things I finally put new Cats on it. The resonator pipie should have beed replace (bad O2 boss) but I was in a hurry.

All ran fine for abour 200mi and through the same code. I reset it and back on after 30mi over and over.

Thought? The right valve cover gasket has a good leak. Could this somehow contaminate the sensor from the outside?

Changing gaskets today and trying a new sensor. And experience would be helpful.

 

The least costly is to swap downstream sensors and see if code changes to 420 but a new sensor definitely cheaper than replacing Cat.

 

Make sure to clean off all residue of old seal. I wire brushed faces, and then vacuumed out tail pipe just in case anything got in there. I am struggling with P0420 code still.

 

It's got 2 new CATs. Should have replaced the resonator pipe at the same time (bad O2 boss). Jury rigged it, ran fine for 200 mile ans started throwind cones again. New resonator pipe and got a new sensor yesterday. We'll see.