Pickup 2WD L4-2559cc 2.6L SOHC (4ZE1) (1993)
Oxygen Sensor: Testing and Inspection
Inspection of HO2S
The output voltage of the H025 can be checked with a voltmeter having a minimum input resistance of one megohm.
1. Disconnect the HO2S from the vehicle harness.
2. Insert a jumper with exposed wire between the sensor and vehicle harness connectors.
3. Set the voltmeter to the approximately two volt range.
4. Connect the positive (+) lead of the voltmeter to the jumper and the negative (-) lead to vehicle ground.
5. Start the engine and run at elevated speed until the emission system has gone "closed loop". The meter should move between approximately 0.50
and 0.80 volts.
Output Voltage, Normal and Abnormal
(A) Reading output voltage of circuit (26) and Engine Control Module
Reading is steady or with slight fluctuation, and is under O.3V or above O.6V.
Reading is between O.3V to O.5V.
(B) Reading output voltage of Heated Oxygen Sensor