B7: Check For O2 Sensor Failure

With the conditions held as in B6, run the engine at 1500 rpm for approximately 2 minutes.

- Does the displayed voltage drop below 400mV and rise above 500mV, cycling approximately every 4 seconds?

Yes
GO to B9, B9: Heated O2 Sensor Short Circuit to Ground

No
Renew O2 sensor, reconnect plug(s).
GO to B8, B8: Stop