F7: Check For O2 Sensor Failure

With the conditions held as in F6, 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 F9, F9: Heated O2 Sensor Short Circuit to Ground

No
Renew O2 sensor. Reconnect plug(s)
GO to F8, F8: Stop