How do you fix P1155 on 2002 Toyota RAV4?

The P1155 code on a 2002 Toyota RAV4 indicates a problem with the air-fuel ratio sensor (A/F sensor) in the engine. To fix it, first check the wiring and connectors for any damage or corrosion, as these can cause signal issues. If the wiring is intact, the sensor itself may need to be replaced. After replacing the sensor, clear the code from the vehicle's computer and take it for a test drive to ensure the issue is resolved.