Euro cats: require lengthened EGT/O2 sensor wires?

[Cubieman]

I simply re-installed the sensor bracket with its built in shims. But I may do what you suggested to clean it up maybe. Props on bringing that up, I almost messed up my beauty cover when I removed that bracket.

EDIT: Missed the bracket relocation part. Why didn't I think of that

[Casa de Mesa]

I wanted to point out as I have seen others relocate the stock US rear o2 sensor plastic bracket from atop the valve cover to the driver side tunnel and did not shim the studs it normally mounts to on the valve cover. If you do not install shims on the studs then the plastic "M" cover won't sit level (have seen cars have a rattle due to this) and you can even crack it when installing the nuts that secure it.

You can get qty (2) of Genuine BMW OE shims which is part number 11127832085 or just source a generic spacer/shim from a hardware store and size it to the same stack height as the bracket. I can measure a shim later but off the top of my head I want to say it's ~5mm thick.

Love this forum! Thank you for that tip!

And relocating the stock bracket is an interesting idea. Will have to think about that.

[Casa de Mesa]

I took the EGT down the drivers side. I really don't think it would have worked otherwise, I could be wrong..

Cool. I'll find out this weekend and take some photos on what I end up doing. Some of this might have to do with where the EGT port is located on the new headers I suppose...?

Not sure if the OP already figured this out but the timing of your question was perfect. I was literally going to post the same topic when I saw yours.

[Cubieman]

The EGT on the Euro sec. 1 sits approximately where the door handles are (as far as how far back it is) the o2's are a bit further yet. I sliced my conduit from the beauty cover all the way to where it turns into a rubber protective kind of piece that goes into the DME area, I actually ended up with about 10-12" extra EGT wiring than I needed, but the o2's were just right. Just seal it up WELL where you have the wiring comming out of your split conduit near the DME area. You will notice that on of the the cabin air filter drain boots (driver's side) basically drops water right on top of this area where you will have the cut the factory loom.

[heinzboehmer]

Is it possible to depin the sensor connectors and pull the wires out of the conduit instead of cutting it?

[e46mpwrd]

Back on the old forums there was a large post about this from what I remember. There is def enough length as others have said, you can also order the euro engine trans harness (dont have the part number but I can edit later, was a pain to get though). This comes with even longer o2s that you do not have to cut out. Not to much work from what I remember (I did it a while ago). After I cut up the old original harness to make a bench harness.

[8000RPM]

I thought I remember someone (maybe Terra) on M3F buying the euro harness and it wasn’t plug n play like you would think. I believe there was still wiring to do in the end.

[Cubieman]

https://www.ecstuning.com/b-genuine-bmw-parts/harness/12517835524/

I think this is the US part.

[e46mpwrd]

https://www.ecstuning.com/b-genuine-...s/12517835524/

I think this is the US part.

I believe that is the Euro part 12517835524 and US part No. is 12517835540. I just checked realoem, but anyone correct me if I am wrong. I also believe this can be just swapped. I did it a couple years ago now but I do not remember any wiring needed to be done. Should be noted that those part number are for 6MT 03+ only.

[repoman89]

I swapped for the Euro harness back when it was like $250 ($550 now, holy crap). Also have the correct plastic mounting pieces underneath. There is no wiring that needs to be done, but the O2 sensor part numbers are slightly different all around. Three of them are found in the US setup but go in different places, so you just move them. One of the post cats is Euro-specific and costs about $250 from BMW, but I found the Bosch generic for $50 shipped on eBay from Latvia. You can shave down the connector and shorten the wiring of the last US one, but meh, $50 for the proper one ..

I had the modified US setup for a couple years but hated how ratty the rewrapped loom got

[e46mpwrd]

I had to double check what I paid back in '17. About half the price, crazy. Really clean install with bracket and harness once your all done though 😁. repoman89 is correct about the sensor parts.

[lemoose]

I was under the impression that the DME could trigger cat protection even without the EGT sensor by calculating the temperature through other sensor variables (o2, AIT, timing etc)- is that not right? In any case, how easy is it to get into cat protection- type temperatures? Will a 4th or 5th gear pull to redline put me in the danger zone?

[heinzboehmer]

Is it possible to depin the sensor connectors and pull the wires out of the conduit instead of cutting it?

For posterity, yes, it is possible.

https://nam3forum.com/forums/forum/main-forum/member-build-journals/13854-heinzboehmer-s-2002-topaz-6mt-coupe?p=131221#post131221

[PSUEng]

Getting my wires ready for the exhaust install and am at a point where I need to cut the beauty cover grommet that holds the four O2 sensor & EGT pigtails, in order to remove the Post Cat/EGT wires. Can anyone advise on the best location to cut this grommet to extract the wires? I'm thinking, cut on the side opposite that of the one that is pre-cut for the single, conduit wrapped pigtail that clips into place. Cutting this way would leave the center of the grommet in tact and maintain separation between the O2 wires and the other little conduit-wrapped wire on the other side. Or, am I just over thinking this?

[Dxj]

I did it as you’re suggesting and it worked out.