DTC P0420: Catalyst System Efficiency Below Threshold (Bank 1) & DTC P0430: Catalyst System Efficiency Below Threshold (Bank 2): Notes
WARNING: This page is about a different car, the 2003 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Bank No. 1 is also know as right bank (RH). Air/Fuel (A/F) sensor refers to sensor closest to engine block. Heated oxygen sensor No. 2 refers to sensor farthest away from engine block.