With GST

Start engine and warm it up to normal operating temperature.
Set voltmeter probes between ECM terminal 114 [HO2S1(B1) signal] or 115 [HO2S1(B2) signal] and ground.

Fig 1: Checking Voltmage Between ECM Terminals & Ground
Courtesy of NISSAN MOTOR CO., U.S.A.
Check the following with engine speed held at 2,000 RPM constant under no load.
- The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V more than 5 times within 10 seconds.
  1 time: 0 - 0.3V --> 0.6 - 1.0V --> 0 - 0.3V
  
  2 times: 0 - 0.3V --> 0.6 - 1.0V --> 0 - 0.3V --> 0.6 - 1.0V --> 0 - 0.3V
- If NG, go to DIAGNOSTIC PROCEDURE .