With GST
- Start engine and warm it up to normal operating temperature.
- Set voltmeter probes between ECM terminal 35 [HO2S1 (B1) signal] or 16 [HO2S1 (B2) signal] and ground.
- Check the following with engine speed held at 2,000 rpm constant under no-load.
- The voltage should go above 0.70V at least once.
- The voltage should go below 0.21V at least once.
- If NG, go to "Diagnostic Procedure ".