Testing & Mixture Adjustment Nissan Stanza II

1. Disconnect negative battery cable. Disconnect ECU connector (16-pin on 200SX; 20-pin on Stanza & Stanza Wagon). Unplug harness connector at oxygen sensor and ground connector lead with jumper wire.
2. Using an ohmmeter, check continuity between body ground and ECU connector pin No. 24 on 200 SX or No. 4 on Stanza. If continuity does not exist, repair or replace harness. If continuity exists, reconnect negative battery cable and harness connector at ECU.
3. Disconnect harness connector at cylinder head temperature sensor and connect a 2500 ohm resistor between harness terminals. Warm engine to operating temperature. Accelerate engine 2-3 times and return to idle.
4. Insert CO probe more than 16" into exhaust pipe and check CO reading. If mixture is correct, disconnect resistor from temperature sensor connector and reconnect sensor. Turn ignition off and reconnect oxygen sensor. Warm engine to normal operating temperature. Ensure Green inspection lamp flashes at least 9 times in 10 seconds at 2000 RPM.
5. If CO reading is not correct, turn ignition off. Remove jumper wire from oxygen sensor harness and reconnect oxygen sensor. Remove airflow meter. Remove airflow meter. Drill a hole in variable resistor (air by-pass screw on 200SX) seal and remove seal. Reinstall airflow meter. Warm engine to operating temperature.
6. Adjust CO level by turning variable resistor (air by-pass screw) on airflow meter until Red and Green ECU inspection lamps blink together. After adjusting CO level, disconnect resistor from temperature sensor connector and reconnect sensor.
7. Turn ignition off and remove airflow meter. Install new seal over variable resistor (air by-pass screw). Reinstall airflow meter and ensure engine runs smoothly. Recheck timing, idle and CO level.

IDLE SPEED & CO LEVEL