How can I fix codes P1135 and P1155

ALEXRAY

MEMBER
2000 LEXUS RX 300
3.0L
V6
4WD
AUTOMATIC
99,230 MILES

Please how can I fix this, after I check the code.
1. P1135 it said air/fuel ratio sensor 1, bank 1-heater circuit malfunction.
Wiring, air fuel ratio sensor ECM.
2. P1155 air/fuel ratio sensor 1, bank 2- heater circuit malfunction.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

Oxygen sensors don't work until they're up to about 600 degrees Fahrenheit. They have electric heaters in them to get them there faster after engine start-up. To have the same fault code for multiple sensors suggests there's a broken wire going to those sensors.

Bank one and two refer to the two sides of the engine. Sensor one refers to the sensor in front of the catalytic converter.