You might want to rethink the O2 sensors.

Basically this means that the oxygen sensor downstream of the catalytic converter on bank 2 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.

 

I did the sensor extension on the up stream O2 sensor. so, I might go try it on the down stream..

if the extension still not work out, that might be the cat's issue?
any recommendation for the good cat converter beside the Toyota OEM? OEM just cost arm and leg.uu

Thank you

 

P0430 occurs when the bank 2 (Passenger Side) downstream (PAST the catalytic converter) O2 sensor is detecting that the converter is not working as efficiently as the specifications say it should.
There are a few common causes. Among them are exhaust leaks, failing O2 sensor(s), engine misfires, leaking/faulty fuel injector(s), leaking head gaskets, internal engine damage or a failing catalytic converter.

The use of spark plug non-foulers or "spacers" is intended to artificially create a difference in readings between the upstream and downstream O2 sensors, thus fooling the ECM into thinking there is a difference in sensor readings, thus showing (false) cat efficiency. To do this, one would use the spacer on the downstream O2 sensor. I would advise against this, however, as you are ignoring another, potentially greater issue.

Catalytic converters are not a wear item. Other external conditions can cause them issues, like excess oil consumption which could coat the interior platinum-palladium and prevent it from doing its job. Rust or rot holes could develop causing leaks or they can be physically damaged by impact.
But otherwise, they should last a VERY long time. Virtually forever.

I would start to look deeper into other potential root causes.
Remove the non-fouler and start looking for exhaust leaks and misfires first. Start checking spark plugs and ignition coils and then finally testing O2 sensors, in that order.
Once you've ruled out all other potential causes, THEN start looking into replacing the cat. It's the least likely culprit in my opinion and is also the most expensive.

Good luck and let us know what you find.

 

Thanks for great information.
I will start to do that step by step...