Judging from your results I'd say cleaning the connector pins is what did the trick. However, the problem is likely to reoccur once oxidation starts forming on the pins again. To keep that from happening it's likely you'll end up having to squeeze each female half of every pin connector to make them nice and tight.

 

Uh oh. I put a Bosch o2 in there. Think that's the problem?

 

Many have claimed that Bosch O2 sensors aren't very good.