This should give you option to download the 2014 on Classic parts manual in pdf format
https://www.4shared.com/office/p6q2v_Zpee/Classic-2014-on.html

This includes wiring sub diagrams specific to each aspect of the 3.7 V6 Roadsters electrics.

or you could just view/save image below of O2 sensor wiring.

[Linked Image]

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone