Hi. I have an ls430 2004 model. Recently check engine light went on and had my auto-shop check it out. He said that this code is showing up.

P0430 "catalyst Efficiency below threshold (bank 2)"

Auto shop says its just the driver side Catalytic Converter.

I had replace the converters at 183,000 miles 16 to 18 months ago at the dealer and now i have 238,000 miles on my car. My dealer said only one year warranty on the converters. So, that warranty is over.

Now, the car is running good but i can't pass inspection because I am due for it soon.
As i was reading the forum, i am not sure what to replace. The "oxygen sensor" or the "converter". Is it possible that just the "oxygen sensor" might not be working properly. Its not showing up in emission hook-up scope that the auto-shop is using. I have never replaced the "oxygen sensors" unless the dealer did it when they replaced the converters at 183,000 miles. If someone had similar problem let me know how to deal with it. Thx.

 

I would go back to the dealer where you had the work done at first since u spent money with them, they may give a discount if complain to the right people . I thought bank 1 was driver side and bank 2 passenger.

 

the cheaper option is to try replacing the downstream 02 sensor first.

rockauto.com carries oem denso ones

 

Problem is likely a leak in the exhaust pipe after the secondary O2 sensor underneath the SST heat shields. I just went through this saga myself. Fix was a simple weld job to seal the leaks.

http://us.lexusownersclub.com/forums...howtopic=70886

 

can we see a pic of this car, is it still looking good after all those miles?

 

where is bank1 and bank2? I am confused about it. I get the code(P0430) in bank 2. My repair man says its the driver side but the posts say passenger side. Help Please. Thx.

 

From the pic below, it's on the passenger side. Recheck if any O2 sensors being change as real high milages. Please go with OEM whether cat or O2 as aftermarket can go out anytime and don't last very long.

 

I am facing sudden P0420 & P0430 simultaneously, & strong gasoline type exhaust smell around & inside car. No one confirms it to be exhaust leak. I am completely lost. Could u tell how u identified the leak. Was it so obvious or hard to find

 

With car off. Blow a shop vac or leaf blower up the tail pipe. Spray bottle with soapy water, squirt all around the catalytic converters and all pipe joints etc. unless will appear wherever your leak is. May need to have it welded up or replaced. I fixed my p0420 with $5 of high temp muffler cement, as it was a tiny leak.