DTC P0420 & DTC P0430: Notes

WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.

Code Definition

DTC P0420: Catalyst System Efficiency Below Threshold (Bank No. 1)
DTC P0430: Catalyst System Efficiency Below Threshold (Bank No. 2)

NOTE: Bank 1 is also known as right bank (RH). Air/Fuel (A/F) sensor refers to sensor closest to engine block. Heated oxygen sensor No. 2 refers to sensor furthest away from engine block.