P0430

[lexus22]

Code P0430 has come up on my is300, have cleared it a few times but comes back after couple of days., reader shows "catalyst System Efficiency Below Threshold Bank 2"

I assume this is the Lambda sensor that requires the drivers seat to be removed to unplug it..? Anyone done this before? 

[chrisgixer]

Nope. It is the related to the efficiency of the pre cats themselves located in the exhaust manifold....not the main bigger cat.

the fix is to weld in a new 02sensor boss positioned after the main bigger cat and relocate sensor 2 from each bank there. The main cat will then clean the exhaust gasses and put the light off. I don’t know if the sensor wires are long enough to reach they may need to be extended. 

 

Sounds a pita but Bosses are freely available and you’ll need someone who can weld, but it’s by far the cheapest fix compared to new Lexus cats or aftermarket ******* that doesn’t work. It is NOT an 02 sensor fault.