Nox Sensor Problem (P229E, P229F)

[gorizonta]

Greetings to everyone.

I'll try to be as short as I can.

I bought my 2014 X5 35d February, last year in USA and exported it to Georgia (East Europe). Car has 110k miles on it. When the car arrived here it had 1/4 fuel in tank. (I did not add fuel to it as I wanted to experience difference (if any) between our and US fuel). While driving the car from port to home after 10-15km (6-9 miles) CEL came on. I immediately stopped connected the OBD scanner to it and read the code. There was only one code present, P229E. After that I continued driving for 100 km (60 miles) on a highway. When search online for that code, I found that it was a bad downstream nox sensor. It seemed kind of odd as the car did not have that CEL light in USA as my friend (who bought the car) drove it from New Jersey to New York port, I decided to buy a new sensor but only after checking the code once again with a mechanic, who confirmed that the sensor needed to be replaced. I order an aftermarket sensor as I was not able to find / order OEM ones. After installing new sensor and clearing the code everything seemed to be fine, but after 70-80 km (43-50 miles) CEL appeared again with a new code, P229F which is downstream nox sensor performance / range.
Mechanic, who suggested that the sensor needed replacement, now suggested to add DEF to the car. For some reason I am unable to see the level of adblue in vehicle information menu in idrive. I added 10 liters (2.65 us gallons) to the car 5 to the active tank and 5 to the passive tank with no issues or overfilling, but that did not help, then they tried to measure DPF delta pressure (I don't know why) which was also good. The next step they suggested is to see if DEF injection nozzle or DEF pump are working properly (as the car was sailing over the Atlantic for a month and throughout the whole trip (3 months) car was not started once which may have caused DEF to crystalize and now that might be preventing injection into the exhaust). I have not checked that yet but I will in near future. What I wanna know is that does that new sensor need any kind of software coding to be done ? I've read on some forums that when replacing nox sensor, adaptions need to be reset / relearned but my mechanic knows nothing about it. I've contacted other mechanics regarding adaption reset but none of them were able to help me.

From the drivers perceptive, car is working ok. I am not noticing any decreases in power, idle is not rough at all and I am averaging 8.2 liters to 100 km (28.5 us mpg) which seems fine.

One last thing worth mentioning might be that when the original sensor was installed on the car, after clearing the code P229E, it would return while driving (without restarting the engine) for 10km-40km (6-24 miles) depending of how aggressively you would drive (that also seems kind of odd as if the sensor has electrical issue why would it take sometimes 10km and other times 40km to detect it, should not electrical problem be detected right away ?). When car is fitted with that aftermarket sensor it never appears when engine is on (without restart). I have even driven 260 km (160 miles) on a highway, without CEL appearing. You have to turn the engine off and when turned on again, it appears immediately. For this to happen you have to drive at least 60km (36 miles) and turn off / on the car more than 2 times (at least from experience it seems so).

P.S. In Carfax report I see that DPF has been changed and EGR system has been serviced right before I bought it.

Thanks to all for your responses.

[RED_Y_]

I did have P229E once, had CEL for 3-4 days and it went away, since my car was under warranty at the time dealer run diagnostics checked the DEF system and replaced NOX sensors "just in case". I might need to dig my service records to find one for this but I think there are 2 sensors. It sounds like you need to get ISTA and run some tests, it will provide you a clear plan on repairs. Check this thread here:
https://f15.bimmerpost.com/forums/sh....php?t=1568962
On the other hand, what kind of emissions regulations you have in Georgia? If they are not too strict you might want to consider going this route:
https://f15.bimmerpost.com/forums/sh....php?t=1525210
And forget about these issues for good.
Edit: Found the work order for it. Pic attached.

[gorizonta]

As far as I know there are no regulations except for CO contents in exhaust, of which this particular car showed to have exactly 0 at idle and 0.001 at 3500 RPM, even my old E46 is able to pass that test with 0.6 of CO (max allowed is 0.8) and clearly visible smoke coming from exhaust. I've taken a look at that "ABC Delete" but I am hesitating as there are elections coming up and new parties might change those regulations. I'm definitely looking forward to "ABC Delete" if those regulations stay as they are.

At the end of the attached image I can see that they ran "RESET CALIBRATIONS FOR NOX SENSORS" so I assume that in my case that needs to be reset as well. Thanks for the reply, I appreciate it.

[RED_Y_]

Yep, get ISTA it will allow you to do calibrations as well as clear errors and troubleshoot properly.

[gorizonta]

I did not want to post here before I had a definite solution, which I have now. DEF injector had no issues at all. Did the spray test via ISTA and it sprayed like a champ. At the end, that after market sensor turned out to be a bad quality or damaged in the shipping process, because it was giving out all kinds or readings (checked via ISTA and card scanner app). What I did was I bought a low mileage used sensor (for fair price), reset the adaptions via ISTA and the problem is gone. It's been a month and 650 km (400 miles) without CEL.

[RED_Y_]

Glad to hear that! Enjoy your car now.