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Oxygen Sensor: Testing and Inspection

Component Inspection

HEATED OXYGEN SENSOR 1 HEATER




1. Check resistance between HO2S1 terminals as follows.
2. If NG, replace heated oxygen sensor 1.

CAUTION:
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Component Inspection

HEATED OXYGEN SENSOR 2 HEATER




1. Check resistance between HO2S2 terminals as follows.
2. If NG, replace heated oxygen sensor 2.

CAUTION:
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897- 18 or J-43897-12 and approved anti-seize lubricant.

Component Inspection

HEATED OXYGEN SENSOR 1

With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select "MANU TRIG" and adjust "TRIGGER POINT" to 100% in "DATA MONITOR" mode with CONSULT-II.




3. Select "HO2S1 (B1)" and "HO2S1 MNTR (B1)".
4. Hold engine speed at 2,000 rpm under no load during the following steps.
5. Touch "RECORD" on CONSULT-II screen.







6. Check the following.
- "HO2S1 MNTR (B1)" in "DATA MONITOR" mode changes from "RICH" to "LEAN" to "RICH" more than 5 times in 10 seconds.
5 times (cycles) are counted as shown at right.
- "HO2S1 (B1)" voltage goes above 0.6 V at least once.
- "HO2S1 (B1)" voltage goes below 0.3 V at least once.
- "HO2S1 (B1)" voltage never exceeds 1.0 V.

CAUTION:
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 35 [HO2S1 (B1) signal] and ground.




3. Check the following with engine speed held at 2,000 rpm constant under no load.
- The voltage fluctuates between 0 to 0.3 V and 0.6 to 1.0 V more than 5 times within 10 seconds.
- The maximum voltage is over 0.6 V at least 1 time.
- The minimum voltage is below 0.3 V at least 1 time.
- The voltage never exceeds 1.0 V.
1 time: 0 - 0.3 V -> 0.6 - 1.0 V -> 0 - 0.3 V
2 times: 0 - 0.3 V -> 0.6 - 1.0 V -> 0 - 0.3 V -> 0.6 - 1.0 V -> 0 - 0.3 V

CAUTION:
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Component Inspection

HEATED OXYGEN SENSOR 2

With CONSULT-II




1. Turn ignition switch ON and select "DATA MONITOR" mode with CONSULT-II.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.




6. Select "FUEL INJECTION" in "ACTIVE TEST" mode, and select "HO2S2 (B1)" as the monitor item with CONSULT-II.




7. Check "HO2S2 (B1)" at idle speed when adjusting "FUEL INJECTION" to ±25%.
"HO2S2 (B1)" should be above 0.63 V at least once when the "FUEL INJECTION" is +25%.
"HO2S2 (B1)" should be below 0.50 V at least once when the "FUEL INJECTION" is -25%.

CAUTION:
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Without CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for atleast 1 minute under no load.
4. Let engine idle for 1 minute.




5. Set voltmeter probes between ECM terminal 74 (HO2S2 signal) and ground.
6. Check the voltage when revving up to 4,000 rpm under no load at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.63 V at least once during this procedure.
If the voltage is above 0.63 V at step 6, step 7 is not necessary.

7. Keep vehicle idling for 10 minutes, then check voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in 3rd gear position.
The voltage should be below 0.50 V at least once during this procedure.

8. If NG, replace heated oxygen sensor 2.

CAUTION:
- Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

AIR FUEL RATIO (A/F) SENSOR 1 HEATER




Check resistance between terminals 3 and 4.
Resistance: 2.3 - 4.3 Ohms [at 25 °C (77 °F)]

Check continuity between terminals 3 and 1, 2, 5, 6, terminals 4 and
1, 2, 5, 6.
Continuity should not exist.

If NG, replace the A/F sensor 1.

CAUTION:
- Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new A/F sensor, clean exhaust system threads using Heated Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.