Euro header + section 1 swap question

[Way2Slow]

Hi everyone, I'm in the process of swapping my US spec headers and section 1 to Euro spec. I've read a couple posts on here that say to make the original O2 sensors reach you can uncoil the slack in the harness from under the valve cover but no one mentions the EGT sensor. I cant get this reach the new location, is there a way to do so without extending it? I'm in California and would like to keep the car smog compliant so I reeeeally don't want to code out the post cat O2 sensors or the EGT if possible.

Any tips or pointers would be greatly appreciated.

[Slideways]

For both the rear O2s and the EGT, you have to carefully cut open a short portion of the loom that routes over the engine and run the wires down the driver's side of the transmission.

[Cubieman]

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/542-extending-o2-wiring-for-section-1-with-cats-repost-pdf

[Way2Slow]

For both the rear O2s and the EGT, you have to carefully cut open a short portion of the loom that routes over the engine and run the wires down the driver's side of the transmission.

Ah.. I was afraid someone would say that.

[Cubieman]

You can always but a Euro harness. $$$

[heinzboehmer]

Ah.. I was afraid someone would say that.

Better option is to remove the harness from the car, depin the connectors, extract the wires and run a new loom down the transmission tunnel: https://nam3forum.com/forums/forum/m...221#post131221

[Cubieman]

Better option is to remove the harness from the car, depin the connectors, extract the wires and run a new loom down the transmission tunnel: https://nam3forum.com/forums/forum/m...221#post131221

I wish I would have done just that, I do not like making permanent modifications on my M3 if it's not necessary. That said, I have a VinceBar..

[Ramps]

I ran euro cats for years and the O2 and EGT both reached without issue. Transferred them over to my catted SsV1 section 1 too, never had to extend anything. Are there variants in harnesses? I routed mine over the trans and along the driver side of the transmission tunnel.

[bavarian3]

Also did not want to make permanent modification, so I coded out the sensors. Just smogged last month. No regrets.

This is with euro headers and HJS cats welded in.

[Way2Slow]

I ran euro cats for years and the O2 and EGT both reached without issue. Transferred them over to my catted SsV1 section 1 too, never had to extend anything. Are there variants in harnesses? I routed mine over the trans and along the driver side of the transmission tunnel.

I was asking if they would reach without rerouting the cables on the driver side. It sounds like no. I didn't realize the euro version ran that way too.

Also did not want to make permanent modification, so I coded out the sensors. Just smogged last month. No regrets.

This is with euro headers and HJS cats welded in.

You smogged with both of them coded out and still passed?? Are you in California?

[bmwfnatic]

You can always but a Euro harness. $$$

I have a few used ones for not too much money, for SMG.

[bavarian3]

You smogged with both of them coded out and still passed?? Are you in California?

yes and yes.

[Way2Slow]

I have a few used ones for not too much money, for SMG.

yes and yes.

Good to know on both accounts. I'm going to try to reroute the cables tonight and if they give me a hard time I may end up doing a combination of both. I.e. code them out until I can get a euro harness then run the cables at a later date. Thanks everyone!

[Tbonem3]

yes and yes.

So you forced readiness? Or got lucky that the monitor stayed green? You can't pass smog in CA without working o2s unless you're spoofing the ecu. Not only is there a monitor for the o2s, there's a CAT monitor that relies on said o2s.

[bavarian3]

So you forced readiness? Or got lucky that the monitor stayed green? You can't pass smog in CA without working o2s unless you're spoofing the ecu. Not only is there a monitor for the o2s, there's a CAT monitor that relies on said o2s.

I didn't do anything other than code out the rear o2's and EGT via Martyns bin tool.

I tested for readiness beforehand, no issues.