E46 M3 Bosch Oxygen Sensor guide

[Riley]

This is exactly what I did. I have only driven it a little since installation, but so far no problems at all. It seems clear that the only differences between the four sensors really are just the connectors and wire lengths.

That is exactly the difference between all the sensors. They are all identical narrowband sensors with just different wire lengths and keyed connectors.

[SkunkWorks]

This might be a dumb question but in the process of installing the M3 exhaust on the wagon and I can't figure out where the square rubber wire holder with the 2 rectangular cutouts for the post-cat O2 sensors goes. Anyone know?

[Slideways]

This might be a dumb question but in the process of installing the M3 exhaust on the wagon and I can't figure out where the square rubber wire holder with the 2 rectangular cutouts for the post-cat O2 sensors goes. Anyone know?

There is a cutout in the plastic beauty cover for rubber block.

[Tbonem3]

Passenger side back towards the CPS. It acts as insulation for the beauty covers hole where the o2 wires and egt go. If I'm thinking of what you're describing.

[SkunkWorks]

There is a cutout in the plastic beauty cover for rubber block.

D'oh! Of course. Thanks you two. The beauty cover has been off the motor for so long I forgot that was even a thing...

I found the insulator hanging on the wire right beside the post-cat O2 sensor so had wrongly assumed it went under the car somewhere 😅