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 terminals 91 [heated oxygen sensor 1 bank 1 signal], 92 [heated oxygen sensor 1 bank 2 signal] and engine ground, and ECM terminals 88 [heated oxygen sensor 2 bank 1 signal], 90 [heated oxygen sensor 2 bank 2 signal] and engine ground.

Fig 1: Identifying Overall Function Of Three Way Catalyst
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 88 and engine ground, or 90 and engine ground is very less than that of ECM terminals 91 and engine ground, or 91 and engine ground.

Fig 2: Identifying Overall Function Of Three Way Catalyst
Courtesy of NISSAN MOTOR CO., U.S.A.

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 (manifold) does not operate properly. Go to DIAGNOSTIC PROCEDURE .

NOTE: If the voltage at terminal 92 or 91 does not switch periodically more than 5 times within 10 seconds at step 5, perform trouble diagnosis for DTC P0133, P0153 first. (See DTC P0133, P0153 HO2S1 .)