O2 Sensor Diagram

[Kdubski]

Had some "help" with an engine rebuild recently. Turns out they didnt mark the O2 sensors in a way that I can recognize which one goes where (same color paint pen on all ).

Anyways, I remember a great graphic that was on the old M3Forums that identified the location of the sensor based on the inside of the connectors. Does anyone remember this thing?

[Tbonem3]

Dafoe's graphic seems to be gone, I can't find it. You can check each plugs' part # and the connector color/shape on ECS's catalog. Pre cat should be your priority. There's a green and a yellow. The yellow is a simple pattern that's repeated in the post cat pair along with a more complex yellow pattern. Beyond getting the connections correct, you also have to have the correct sensor in the correct header bank.

[Cubieman]

Damn. I've got it on my other phone, I'll post it up when I get home.

[Cubieman]

[Tbonem3]

Nice! Maybe edit it to show the first plug is light green, then the last 3 are all yellow.

IIRC, the thread had pictures of each connector as well. At least you can see them on ECS.

[Cubieman]

Somewhere I've got a PDF I think Turner made that had the pictures of each connector

[Pnick]

Here you go guys...hope this helps...one way or another.

O2-sensor plugs are uniquely keyed. Trick is, knowing what bung they should go...

Installing headers rule of thumb is to mark the wires on each side the plug before unplugging them up top. I use different color tape... remove the headers with the O2's installed, and then transfer them to the new headers/cats one at a time. After install, plug them in to the corresponding marked colors.

Anyway, here are the pics and location of each sensor looking at the plug closely you can see they're all different. The pre-cats are easy, as they're different colors. The post cats are both yellow, but keyed slightly different.

Give credit to Dafoe!!!

Bank 1 (cyl 1-3) (Long Header) Pre-cat O2


Bank 2 (cyl 4-6) (short Header) Pre-cat O2


Bank 1 (cyl1-3) (Long Header) Post-cat O2

Bank 2 (cyl 4-6) (short Header) Post-cat O2

That’s all folks!

[Casa de Mesa]

Brilliant! Using this post this weekend!

[Kdubski]

Wow this is a life saver. Thanks DaFoe and everyone else!

[et89]

Reviving this because my S54 is a Z4 model that i am converting to MSS54HP and swapping it into my e36.
this means I am missing the correct O2 sensor harness and need to create my own.

Can anyone share the female plug partnumbers on the harness? (So not the plugs on the O2 sensors but the partnumbers where they connect to) I only need the Pre-cat parts.

Edit: I was able to find part numbers for the A. B, C type connectors. will add them to this post later.

Part numbers:
A- 1703570
B- 1740486
C- 1427964