u/No_Cover2208

There is a lot of conflicting info online so I was hoping someone could help. I am trying to adapt my 3-wire O2 sensor (from an early model eta I believe) to the 4-wire connector to plug directly into the engine harness. 1987 325i

Engine harness side
Pin 1 - BR
Pin 2 - BK
Pin 3 - BR
Pin 4 - GN/BU

O2 3-Pin Connector
Two white and one black

O2 4 Pin Connector
Two whites, one Black and one Gray

I tried looking at the ETM for my model year but that confused me a bit more, see picture 2

Hi all, I am swapping my 318is from M42 to M20 (ik ik there are better swaps but this is what I wanted). I am not experienced with wiring but did a lot of research on this so I just wanted to verify with anyone who has more knowledge.

Questions are at the bottom of the image, let me know if there is anything I missed.