DTC P0136: Oxygen Sensor Circuit Fault (Bank 1 Sensor 2) Or DTC P0156: Oxygen Sensor Circuit Fault (Bank 2 Sensor 2): Notes
WARNING: This page is about a different car, the 2003 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Bank No. 1 refers to bank which includes cylinder No. 1. Bank No. 2 refers to bank without cylinder No. 1. Heated oxygen sensor No. 1 refers to sensor closest to engine block. Heated oxygen sensor No. 2 refers to sensor farthest from engine block.