Code P2414 on Z4M?

[VindieselJetta]

Hi all,
My Z4M started idling a little rough recently, finally got a CEL, code P2414. Some quick research indicates that it is probably an oxygen sensor. Any ideas a on which ones I should start replacing?

Thanks!

[vt100]

I'd do all 4 at once. The chances are others will die soon anyway if one has died already.

[VindieselJetta]

Thanks, not a bad idea. Can you confirm there are 2 sensors for cylinders 1-3 and 2 for cylinders 4-6? Total of 4 precat sensors to replace? You think Bosch is acceptable replacement vs BMW oem? They seem to be about half the price.

[vt100]

Originally Posted by VindieselJetta

Thanks, not a bad idea. Can you confirm there are 2 sensors for cylinders 1-3 and 2 for cylinders 4-6? Total of 4 precat sensors to replace? You think Bosch is acceptable replacement vs BMW oem? They seem to be about half the price.

Hmm.. it actually looks like there are 6 in total according to realoem

2 on main cats:
https://www.realoem.com/bmw/enUS/sho...diagId=18_0658

and 4 on pre-cats:
https://www.realoem.com/bmw/enUS/sho...diagId=18_0664

But pelican parts article talks about 4 on pre-cats only:
https://www.pelicanparts.com/techart...eplacement.htm

And folks in the UK say those that fail the most are on pre-cat:
https://z4-forum.com/forum/viewtopic.php?t=12406

Also if you've not seen this yet https://www.zpost.com/forums/showthread.php?t=1459357

PS: sorry, can't recommend the brand. mine are still stock... knocking on wood...

[XMetal]

My understanding is that there are only 4 sensors in US cars. 2 lambda sensors in front of the main cats and 2 oxygen sensors after the main cats. The secondary cats are unmonitored. The main cats are built into the headers. The oxygen sensors in the secondary cats are for Euro cars since there are no cats built into Euro headers

[wdb]

When I did the clutch I took the entire exhaust off my car, from the back of the headers to the tip of the tailpipes. No oxygen sensors on anything back there.