O2 Sensor Wire - single or coaxial?

[sclebo05]

When changing my O2 sensor, the brown plastic plug disintegrated in my hand. Since it seemed to be a 1/4 inch spade connector, I broke off the rest of the plastic and contemplated putting a new connector on the end. What I found under the plastic perplexed me. There is a spade connector connected to an inner stranded wire, but there ALSO seems to be an outer strand that stops short of the spade connector.

Is this some form of shielding or is there a special plug that must be used that somehow uses both the inner and outer strands?

[RRoller123]

Noise shielding. The voltages generated are quite small and subject to interference.

[sclebo05]

That's what it looked like, THANKS for the clarification. Off to get my crimp tool