Im new to this forum because my brother bought a 2004 Endeavor LS 6 cylinder for our mother, the person he bought from was a mechanic, he said th o2 sensor was bad and he had a new one but said he hadn’t had time to put it on yet, And my brother could bring it back to him and he would put it on for him.
i do most all my machanic work so I crawled under it found the sensor, bank 1 sensor 2 and some one went to great pains to remove the sensor harness from the vehicle, I found where it was supposed to be, on a bracket next to bank 1 sensor 1, the bracket was shiny so I know that is where the plug to the sensor plug went.

i looked at the harness to where bank 1sensor 1 entered the main harness and there was about 12 inches of brand new electrical tape, I unwrapped it and found a black with yellow stripe that had a green and yellow wire And
https://cimg7.ibsrv.net/gimg/mitsubi...6650d7c4d.jpeg
Wires that have been cut
stranded aluminum wires, they are two more wires a red and a black with brown stripe.

could these 4 wires be where the harness plug use to be, the plug that would have plugged to th the sensor plug.