I'd say clear it, and see if it comes back.
If it follows you home again, might be worth purchasing a new O2 sensor.
Only thing I can think of might be something with the wires, or maybe how it's connected to the ECU. If it's a "circuit" malfunction, it might not be the sensor itself, but it's hard to say. Check your wiring (if you've touched it at all before) and make sure the sensor is still securely plugged in. Otherwise, I'm outta ideas.
AJ