[guzbya]

Finally wrenched out my upstream NOx sensor out of my 2010 335d and replaced with new one. Sensor tip looked a little different. After I continued to get error codes ( more in fact after replacement ) I checked the part numbers to find out that at some point a mechanic put an oxygen sensor/unit instead of the NOx sensor/unit. Looks like it was a 335i O2 sensor put in place of the 335d NOx sensor. Has anybody ever heard of this? Is this acceptable? Does my ECU need to be tuned again or should I just return NOx and replace with another O2 sensor? Any suggestions would be appreciated.

[floydarogers]

Originally Posted by guzbya

Finally wrenched out my upstream NOx sensor out of my 2010 335d and replaced with new one. Sensor tip looked a little different. After I continued to get error codes ( more in fact after replacement ) I checked the part numbers to find out that at some point a mechanic put an oxygen sensor/unit instead of the NOx sensor/unit. Looks like it was a 335i O2 sensor put in place of the 335d NOx sensor. Has anybody ever heard of this? Is this acceptable? Does my ECU need to be tuned again or should I just return NOx and replace with another O2 sensor? Any suggestions would be appreciated.

It's not acceptable. I've heard of similar things happening with maintenance to our 'd's: certainly oil changes have been screwed up (LL01 rather than LL04). NOx sensors are guaranteed to 10/120K, so go to the dealer and demand things made right.

[guzbya]

So I did a little more research: Someone on eBay labeled the part as 335i O2 sensor.
It looks like there were previous versions of similar part with different part numbers. The one I removed was 13 62 8 509 721. The one I installed is 13 62 8 589 846. There are other iterations. Does this mean I need to have ECU adjusted?

[robnitro]

Usually it's best to replace both up and downstream nox. Yes I heard they updated the part.
Theres an extended warranty for it check bmw-rp.com with your vin. 10y/120k I think...

[guzbya]

I've got 245k miles on it and just did a DIY CBU clean due to numerous codes and it wouldn't pass emissions. Had a persistent P20EE code and figured it was NOx sensor.

[robnitro]

Wow 245k and with dpf/scr! Theres a test in ista-d for the scr /nox sensors...

[guzbya]

Thanks for the tip.
All highway miles. Had DPF tank and SCR replaced at around 130k . Just want to get it through inspection to last 2 more years. It's paid for...

[Yozh]

Of you are getting a P20EE check your car gets up tontemperature.