CEL is now on permanently. What is actually causing the code? The material inside cats not cleaning the exhaust? The honeycomb is broken up?

 

Probably clogged up. I would check fuel trims on bank 2. If you've been running rich for a long time. That will kill the cat soon enough.

 

Try one of these......
Cat de-fouler

It tricks the ecu and takes care of that dreaded check engine light

I had a "friend" with the same problem...this fixed it.

 

^If going that route, I'd recommend getting one with a 90 elbow to it. Longer travel and the O2 sensor is much further away from the exhaust stream.

 

How about a cat cleaner?

 

Sorry to hijack this thread but I have the same code and Im due for inspection in 2 weeks. Is it possible for an exhaust leak thats after the o2 sensor to cause the code? How does the sensor read the air thats already passed it?

 

I also have a 04 GX470 (200k miles) that has this p0430 code. I reset it and off for now but we will see, has not been driven very far/long yet since reset.

I have these readings. Looks like bank 1, sensor 2 and bank 2, sensor 2 are having a problem. Anyone know how to interrupt these codes in the attachment? Sound like a exuast leak on the left side vs a o2 sensor (since 2 of them seem to have it) vs a cat converter?

These are from OBD Fusion




Thanks!

 

Update. I put in spark plug defoulers and passed inspections 3 days before expiration date.