With GST

Start engine and warm it up to the normal operating temperature.
Turn ignition switch OFF and wait at least 10 seconds.
Start engine and keep the engine speed between 3, 500 and 4, 000 RPM for at least 1 minute under no load.
Let engine idle for 1 minute.
Set voltmeters probes between ECM terminal 35 (HO2S1 signal) and engine ground, and ECM terminal 74 (HO2S2 signal) and engine ground.

Fig 1: Setting Voltmeter Probes Between ECM Terminal 35 & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 2: Setting Voltmeter Probes Between ECM Terminal 74 & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
Keep engine speed at 2, 000 RPM constant under no load.
Make sure that the voltage switching frequency (high & low) between ECM terminal 74 and engine ground is very less than that of ECM terminal 35 and engine ground.
Switching frequency ratio = A/B

A: Heated oxygen sensor 2 voltage switching frequency

B: Heated oxygen sensor 1 voltage switching frequency

This ratio should be less than 0.75.

If the ratio is greater than above, it means three way catalyst does not operate properly. GO TO "DIAGNOSTIC PROCEDURE ".

NOTE: If the voltage at terminal 35 does not switch periodically more than 5 times within 10 seconds at step 7, perform trouble diagnosis for "DTC P0133" first. (See DIAGNOSTIC PROCEDURE .)