Originally Posted by awbazar
Can anyone tell me how the wires produce a "clean air reference"? I presume this refers to the leads from the oxygen sensor connector to the sensor itself and has nothing to do with the car side wiring.
It's actually the space around the wires that provides the path for the clean air reference. A splice that blocks the path will block the clean air, thus the warning. Yes, they are talking about the wires on the sensor side of the connector.