Any DIY O2 sensor replacement guide?

[fackamato]

I got the 12b304 code despite clearing it - replacement part is the 11787848486 which I just received, for bank 1, cyl's 1-3. Is there a DIY guide on how to replace this? Mainly looking for how to identify which one it is in the car, before I start removing parts.

Thanks

[TopJimmy]

Short pipe, lower sensor.
I have the same code plus the 404.

[fackamato]

Originally Posted by TopJimmy

Short pipe, lower sensor.
I have the same code plus the 404.

Holy smokes, so it's the pipe to the right / the second one he installs in this video:

It is probably not possible to get to it from above. I'm thinking:

1. Exhaust / midpipe removal
2. Passenger side airbox removal
3. Flashlight + scraped hands + swearing + luck

[TopJimmy]

Originally Posted by fackamato

Holy smokes, so it's the pipe to the right / the second one he installs in this video:

It is probably not possible to get to it from above. I'm thinking:

1. Exhaust / midpipe removal
2. Passenger side airbox removal
3. Flashlight + scraped hands + swearing + luck

Yes, I think the short pipe goes in at 21:53

[BzsBimmer]

This is hilarious. I have the same code… could it be BM3 related? Lol

[fackamato]

I am not so sure now which one it is. https://www.realoem.com/bmw/enUS/sho...88#11787848486 says it is on the left longer downpipe:

[BzsBimmer]

Can someone confirm 12B304 is the longer Downpipe, O2, PN 11787848486 according to Realoem? Other threads show it to be the long Downpipe, not the shorter one mentioned above.

[BzsBimmer]

Bump. Anyone?

[HONGCHUMZI]

Originally Posted by BzsBimmer

Bump. Anyone?

I had the error code P0036,12B304 written above and replaced the O2 sensor behind the long pipe (Bank 1) (Sensor 2, Downstream).

Error code 12B404 is a short pipe. (bank2)

Lambda Sensor for BMW BOSCH 0 258 030 142

You can use it as a replacement.



After finishing the work, you need to delete the error code with the OBD diagnostic device.

[BzsBimmer]

Thanks for the confirmation!

[Cboy]

I'm getting 12b304 which I understand to be post cat bank 1 (long down pipe)

anyone know if this can be done on jack stands from the bottom of the car without removing the downpipe?

[Jbonly21]

Originally Posted by Cboy

I'm getting 12b304 which I understand to be post cat bank 1 (long down pipe)

anyone know if this can be done on jack stands from the bottom of the car without removing the downpipe?

You could, but it wouldn’t be fun. About the same as removing the downpipes.
HOW TO INSTALL BMW F80 M3 AND F82 M4 DOWNPIPES (ARM DOWNPIPES)

[Heronween]

Secondary/post-cat O2 sensors easily replaced without touching downpipes if you have a 22mm Crowfoot or O2 sensor wrench

[deeLow]

Originally Posted by Heronween

Secondary/post-cat O2 sensors easily replaced without touching downpipes if you have a 22mm Crowfoot or O2 sensor wrench

Can you elaborate more? I have to replace a Bank 2 Sensor 2 and have access to an 02 sensor tool, just haven’t done it cause I’m dreading removing the DP’s.