Overall Function Check

Use this procedure to check the overall function of the three way catalyst 1. During this check, a DTC might not be confirmed.

With GST 

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 at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Open engine hood.
6. Set voltmeter probe between ECM terminals 74 [HO2S2 (bank 1) signal], 55 [HO2S2 (bank 2) signal] and engine ground. See Figure.
7. Keep engine speed at 2,500 RPM constant under no load.
8. Make sure that the voltage does not vary for more than 5 seconds.

If the voltage fluctuation cycle takes less than 5 seconds, Go to DIAGNOSTIC PROCEDURE .

• 1 cycle: 0.6 - 1.0 -> 0 -- 0.3 -> 0.6 - 1.0