Where is the Air Fuel Sensor Located on 1999 Toyota RAV4?

If you are refereeing to the downstream or sensor 2 than it is located after the catalytic converter.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

Check your MAF sensor. They get dirty. TPS can fail too.

Air/Fuel Mixture System Lean Bank 1

- Intake air leaks (vacuum leak somwhere)
- Faulty front heated oxygen sensor
- Ignition misfiring - coil, igniton module, distributer malfunction
- Faulty fuel injectors
- Exhaust gas leaks
- Incorrect fuel pressure- fuel filter or weak pump
- Faulty Mass Air Flow (MAF) sensor
- Incorrect Positive Crankcase Ventilation (PCV) hose connection
or bad pcv valve.

******************* most likely vacuum leak

Hi, it's P1135 = A/F Sensor Heater Circuit Malfunction (Bank 1 Sensor 1).
Thats going to be located on the top sensor on the RIGHT SIDE, FACING THE ENGINE from the front.

Here are two of the most common causes of the check engine light.

Most common, MAF ( mass air flow ), sensor. A faulty MAF prevents the computer from determining the correct fuel/air mix ratio.

Oxygen sensor. ( front and rear, front meaning before the catalytic converter, rear meaning after the catalitic converter. The front measures the fuel/air mix being sent through the catalitic converter, the back measures the emmisions and lets the computer know if any fuel/air mix ratios need to be adjusted. Both of these can trigger the check engine light.

I hope this helps you.

air fuel sensor heater circuit response malfuction

Here's what the codes mean:
P1135 Air/Fuel Sensor Heater Circuit Response (Bank 1 Sensor 1)
P1155 Air/Fuel Sensor Heater Circuit. (Bank 1 Sensor 2

This is mainly related to the oxygen sensors. It maybe the sensors themselves or an open wire going to te sensors. They are mainly located on the exhaust pipe. One before and on after the catalytic converter.

The O2 sensor is located on the passenger side of the car. Directly under the front passenger door you will see the exhaust. The wire going up into the floor is connected to O2 sensor 2

its the sensor on the drivers side of the exhaust manifold........ it might be an air fuel ratio meter and not an o2 sensor.. good luck jimmy

Front of the engine, on the cyl head, passenger side