2001 RAV4 - Mode $06 TID $01 CID $02 Error

[frafreg]

Using Torque Pro I got TID 01 CID $02 error.
It says Rich to lean sensor threshold voltage constant
Max: 128 Current: 143

I did some research and for Toyota:
Both TID $01 and CID $01 relate to the catalyst monitor.
TID $01 as Catalyst and CID $01 as Catalyst Deterioration Level for Bank 1.

I got TID $01 as Catalyst and CID $02 as Catalyst Deterioration Level for Bank 2 but not sure.

Could this mean a bad downstream O2 sensor or are the catalytic converters really bad?

I also had error codes P0420 and P0430 indicating bad catalytic converters.
Any help would be appreciated. Thank you.

[Brian R.]

It is very possible that the problem is the Sensor 2. Considering the difference in cost, I would certainly replace the downstream sensor and see if it solves the problem. I don't know of any other sensor which monitors the catalyst efficiency for the ECM other than the HO2 sensor.

[frafreg]

I would like to be able to test the sensor more thoroughly before replacing it. When I reset the codes, the light stays off for almost 2 weeks. I was fortunate enough to pass inspection because it completed and passed all of the monitor tests long enough.