Is it the Catalytic Converter or O2 Sensor? Error Code P0430

[TNT79Bronco]

I have a Durametric reader.  How can I test to see if the post Cat O2 sensor on Bank 2,  is the problem or if it is a bad Cat?  I am getting signals from all 4 O2 sensors, but not sure how to tell if the Cat is doing its job or not.

 

Thanks!

[Ahsai]

Most likely the cat itself with that code because O2 sensors have their own codes.

 

After the engine is fully warmed up, at idle, the pre-cat sensors should swing between ~0.2 to ~0.8v every few seconds while the pos-cat should stay more or less at 0.7v flat. If the post-cat follows the precat voltage pattern, the cat is bad and needs to be replaced.

[JFP in PA]

You need to look at the voltage signals from both sensors on that side: