Pickup 2WD L4-2254cc 2.3L SOHC (4ZD1) MFI (1994)
Oxygen Sensor: Testing and Inspection
1. The output of the oxygen sensor can be checked with a digital voltmeter having a minimum input resistance (impedance) of 1 megohm (1 million
ohms).
2. Proceed as follows:
Fig. 210 Disconnecting Oxygen Sensor Harness
a. Disconnect the oxygen sensor from the vehicle harness.
O2 Sensor
b. Insert a jumper with exposed wire between the sensor and the harness to ease probing, and reconnect connector.
c. Set the voltmeter to the 2 volt scale.
d. Connect the positive lead of the voltmeter to the jumper and the negative lead to vehicle ground.
e. Start the engine and run at 2500 rpm for 2 minutes or until the engine has gone into "closed loop" operation.
f.
The meter should move between approx. 0.50 and 0.80 volts.