DTC P0155: Bank 2 Heated Oxygen Sensor No. 1 - Heater Circuit: Notes
WARNING: This page is about a different car, the 2002 Isuzu Trooper. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Always inspect a faulty Heated Oxygen Sensor (HO2S) for contamination and correct cause before installing a new HO2S. Bank 2 refers to left cylinder bank.