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Hi just wondering how many other users have had trouble with nox sensor. Dash light came on checked fault with Obd Eleven tool said nox sensor. I looked utube and tried cleaning by putting it in a jar of injector cleaner for 24 hours then blew out with carb cleaner. Came home after doing about 15miles light back on my van has only done 30,000 miles and is a 17 plate 4 years old is this a common problem with caddy vans how many others have experienced this.

I have been having trouble with #1 Nox sensor on my 2018 caddy.

The van has recently felt sluggish & poor fuel economy, no management light, did a diagnostic check & had P20EE00 fault stored.

Cleared the fault but came back a few days later, still under warranty so had VW check it over (ferry & over 200 mile round trip) no faults stored when they checked it.

The only thing that I can see on the diagnostic is the live readings for the Nox sensors.
Sensor #1 is 65335 ppm & sensor #2 is 0 ppm

What fault codes do you have & could you compare your live readings with mine please?

I had the same problem at around 50000 miles
Took it to vw and was told the sensor was around £550 fitted
After picking my self up off the floor i said it was out of warranty by 2 weeks
Luckily they did it under warranty
After a bit of investigation this is a common problem if the add blue tank is over filled
You must only fill the add blue the amount indicated on the dash

My fault code comes up as P229 E00 sensor bank 1 sensor 2 it also reads sometimes as p22 A700 nox sensor heater sensor bank 1 sensor 2.I haven't done any live reading on the sensor I could check at the weekend. I didn't know over filling the tank for the adblue can cause this I did over fill it by mistake now looks like I will need a sensor thanks for that info Martin451

No Problem
It didn't make sense to me
I had all sorts of strange errors
Apparently the ECU can not understand how much to inject add blue if the tank is not within a set tolerance

Same here. Initial P20EE code, sluggish performance and poor fuel consumption. Code would reset for upto 2 days but always came back. Tried checking all the wiring, cleaning the sensor, etc but no joy.

Eventually gave in and bought a new sensor (beware of fakes on auction sites) and problem solved.

Found a place selling original continental part £349.99 plus £3. 49 p&p looks like I will bite the bullet and buy one I will never over fill the adblue tank again

Yep mine too 2017 2.0 48K same fault code P20EE Stared bringing on engine management light then resetting itself every few days, now beeps with warning 650 miles then resets itself next time I turn it on. Nice little cash cow for VW

Could anyone check their live data & see what the ppm readings for the sensors are?

@Plumbcaddy
You could be me!
17 plate, < 40,000 miles, last week dash light - U029E "Lost Communication with NOx Sensor".
Any idea if this is such a common fault that it might be possible to get VW to cough up something towards an out of warranty repair?

This dose not look good for long term ownership. I pushed the boat out when I bought my caddy brand new in May 2017 I paid for a highline and a dsg gearbox. At 2years three months old the battery died and need replacing now at 4 years old 30,000 miles it needs a nox sensor if it's going to need one of these things every 4 years its not looking good. Just a side note for Fat Eric I tried looking for the live data readings but I'm not very familiar with the obd eleven reader can you tell me how you got to those live readings as I would like help you out and get you the readings.

@plumbcaddy, I was using an Autel diagnostic computer, there will be an option somewhere for live readings/data.
I will try & put up a photo of the readings from mine.

So is there consensus that this can be caused by overfilling the adblue reservoir? Perhaps confusing the system and causing adblue delivery problems?

I possibly might have added more than instructed by the system - but not on overflow. Plan to very careful in future!

I thought the overfilling issue was just about not spilling it on anything (including yourself) as its highly corrosive rather than it would cause erroneous readings or sensor failures. For that reason I carry a funnel with a valve in it so when the tank (admittedly this is in my Hilux) is full the valve shuts and the stuff left in the funnel gets poured back into the container.

Quick update live readings for Fat Eric my live readings are pretty similar to yours first reading is 62995 second one is zero I have now changed the nox sensor and the ecu for a continental replacement from oe parts Milton Keynes we will now see how it goes.