Code P0136: Heated Oxygen Sensor Circuit (Bank No. 1, Sensor No. 2) Code P0156, Heated Oxygen Sensor Circuit (Bank No. 2, Sensor No. 2): Notes
WARNING: This page is about a different car, the 1995 Lexus LS 400. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Bank No. 1 refers to bank that includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. Sensor No. 2 refers to sensor furthest from engine block.