P1155 on 2002 Lexus RX300. Bank2 sensor1 b4 cat converter didn't fix it. what could it be?

Question

2002 Lexus RX300 code P1155. I changed the bank 2 sensor 1 oxygen sensor (1 of 2 heated oxygen sensors before the catalytic converter) & cleared the code, but I still get trouble light & same error code P1155. It's an expensive sensor, so I don't want to change bank 1 sensor 1 if it's not going to help.
Should the code tell me if it's before or after the catalytic converter? Should the code tell me which sensor if it's before?

Answer 1

HI there, 

This code is for the sensor before the converter on bank 2. There is also a fuse for the heater circuit for you to check. This should be located in the fuse box under the hood. If the fuse is good you may have a faulty ecm or a wiring problem to the computer or sensor.
P1155 LEXUS - Air/Fuel Ratio Sensor Heater Circuit Malfunction Bank 2 Sensor 1

Read more: https://www.autocodes.com/p1155_lexus.html