What have you tried so far? I had the issue on my VR and it turned out to be the brand new sensor I fitted was faulty. I chopped wires and rerun them and it wasn't even the cables.
Also is yours a heated sensor with four wires? Or is it like a VN one? I ask because it gets really messy once you start running new cables when you don't need too. Another thing do you have AED or Tuner Pro? By running engine diagnostics it helps to figure out if it's a cable issue or faulty sensor.
I've tried from 1-5 on the Gregory's manual and I'm pretty sure but not fully its the last thing on there quote taken from manual(if voltage is above 600millivolts, check the circuits and connection between the oxygen sensor, the control unit terminal D6 and the engine earth terminals for continuity. If no fault can be found renew ecu) but reading it out loud when they say check D6 and engine earth terminals do they mean D1,D3,A12 as I haven't done that yet I thought it meant on engine.
2 wires
And I replaced the sensor and then the check engine light was coming on even more and going off but would stay on longer with new one in
And no don't aldl or tunerpro where would I get one of them mate I can't seem to find one for VP commodore