Toyota RAV4 Service Manual: Air fuel ratio sensor

Components

On-vehicle inspection

1. Check air fuel ratio compensation system

1. Connect the intelligent tester to the dlc3.
2. Turn the ignition switch on.
3. Select the following menu items: data list / a/fs b1 s1 and o2s b1 s2.
4. Warm up the a/f sensor with the engine speed at 2,500 rpm for approximately 2 minutes.
5. Keep the engine speed at 2,500 rpm and confirm that the display of "a/fs b1 s1" is as shown in the illustration.

Hint:

• The illustration may slightly differ from the display on the intelligent tester.
• Only the intelligent tester displays the waveform of the a/f sensor.

6. Confirm that the display of "o2s b1 s2" changes between 0 to 1 v with the engine speed at 2,500 rpm.

Ok: the voltage output oscillates more than 8 times in 10 seconds.

Notice:

• Perform the check immediately after warming the engine up.
• If the voltage variation could not be verified, warm up the a/f sensor again. If it could not be verified even after warming up the sensor again, check for dtcs (see page es-292).

Removal

1. Disconnect cable from negative battery terminal

Caution:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to prevent airbag and seat belt pretensioner activation.

2. Remove air fuel ratio sensor (for bank 1 sensor 1)

1. Disconnect the sensor connector.
2. Using sst, remove the sensor from the exhaust manifold.

Sst 09224-00010

Inspection

1. Inspect air fuel ratio sensor (for bank 1 sensor 1)

1. Measure the resistance of the sensor.

Standard resistance

If the resistance is not as specified, replace the sensor.

Installation

1. Install air fuel ratio sensor (for bank 1 sensor 1)

1. Using sst, install the sensor to the exhaust manifold.

Sst 09224-00010

Torque: 40 n*m (408 kgf*cm, 30 ft.*Lbf) for use with sst

44 N*m (449 kgf*cm, 32 ft.*Lbf) for use without sst

Hint:

• Use a torque wrench with a fulcrum length of 30 cm (11.81 In.).
• Make sure sst and wrench are connected in a straight line.

2. Connect the sensor connector.

2. Connect cable to negative battery terminal

3. Check for exhaust gas leaks