[pbedrosi]

AliExpress has them again, around $220-$270 + Shipping from couple of sources.

I did find less expensive ones with lower grade staleness, 201, they say it will corrode but not sure if it matters for headers, its not a show care either.

$80 plus shipping. Also, 02 upstream bungs are in the right spot for our E91.

https://www.aliexpress.us/item/32568...yAdapt=glo2usa

[gaze2]

Originally Posted by pbedrosi

AliExpress has them again, around $220-$270 + Shipping from couple of sources.

I did find less expensive ones with lower grade staleness, 201, they say it will corrode but not sure if it matters for headers, its not a show care either.

$80 plus shipping. Also, 02 upstream bungs are in the right spot for our E91.

https://www.aliexpress.us/item/32568...yAdapt=glo2usa

Ok so, the upstream bungs on the OEM exhaust are on top, where the bank merges so the sensor catches all 3 cylinders. The cheaper aliexpress one you linked which have it on top but on only one cylinder. Although the more expensive aliexpress AA headers seem to have 2 variants one for EU market and one for NA market, and one of them also has the bung on the primary on top...
So it goes like this:

Cheap aliexpress headers:
- primary o2 bungs on top of middle cylinder primary

Expensive aliexpress headers (AA copy) Version 1:
- primary o2 bungs at the collector, next to secondary bungs

Expensive aliexpress headers Version 2 (for europe?):
- primary o2 bungs on top of middle cylinder primary

Why not make all of them have the primary bung on the collector? Why have EU and NA versions of the headers? Are the stock headers different in those regions? On realoem the headers look the same. Maybe the EU version has shorter cables and couldnt reach the bung all the way in the back or something?
I wonder with the "proper" exhaust header having the primary o2 next to the secondary, what would be the problem of just putting the primary o2 sensor in the secondary "downstream" bung on the other designs? Or just making the ECU use the secondary o2 sensor for adjusting AFR and stuff, and plugging the primary and secondary o2 sensors in their respective holes? Is that even possible?
What about the o2 sensor needing to be hot to work properly? Maybe that's why they put it so close to the exhaust valves?

I recently discovered my EU spec 325i with the n52b25 has had its cats removed, but I dont have any CEL or errors so I guess the secondary o2 sensor has been coded out or something. I am trying to figure out what to do, if the secondary o2 sensor isnt working what is stopping me from buying the cheapest header with the wrong bung positions, and just plugging in my primary o2 sensor in the downstream bung?

[Clean328]

Does anyone have an updated link to the headers? The posted one doesn't work anymore. Looking to join the crew lol