With GST

WARNING: This page is about a different car, the 2004 Infiniti G35. However, it is still accessible from the selected car via links, so may be relevant.

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.
Open engine hood.
Set voltmeters probes between ECM terminals 35 [HO2S1 (bank 1) signal], 16 [HO2S1 (bank 2) signal] and ground, and ECM terminals 74 [HO2S2 (bank 1) signal], 55 [HO2S2 (bank 2) signal] and ground.

Fig 1: Overall Function Check (With GST)
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 terminals 74 and ground, or 55 and ground is very less than that of ECM terminals 35 and ground, or 16 and 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 1 does not operate properly. Go to "Diagnostic Procedure ".

Fig 2: Overall Function Check (With GST)

Courtesy of NISSAN MOTOR CO., U.S.A.

NOTE: If the voltage at terminal 35 or 16 does not switch periodically more than 5 times within 10 seconds at step 7, perform trouble diagnosis for DTC P0133, P0153 first. (See DTC P0133, P0153 HO2S1 ).