C7: Check For O2 Sensor Continuity

With EM012 and EM022 disconnected, measure the resistance between EM012/017 and EM022/002.

Is the resistance < 0.5 ohms?

Yes
GO to C8, C8: O2 Sensor Screen Ground Continuity

No
Inspect harness/connectors EM012 and EM022 for corrosion, damaged/pushed back pins. Repair as necessary and reconnect plug(s).
GO to C10, C10: Stop