P20EE NOX CAT efficiency below threshold

I am getting the P20EE reading on my generic code reader and it is indicating it is in bank one and out of range. THe monitor shows a reading of 0.035 with an acceptable range of 0.499 to 65.535. I changed out the NOx sensor after the exhaust valve with no improvement. Should I be looking at another NOx sensor?

Another monitor reading out of range is $02- Exhaust Gas Sensor Monitor Bank 1- sensor 2 with a reading of 187.99 and a range of 50 to 150.

Any information toward fixing this would be greatly appreciated.

Thanks.

have you taken a lot of short trips, urban driving? when my kiddo was born 4 weeks early my Passat only went from the hospital to work and back for a month- a 1 mile trip and I got all sorts of codes like that- after a long hour drive they all went away.

jrm,
No. It has been a combination of long and short trips. Wondering if the pump died as I am getting open circuit readings and all three wires of the pump motor after dropping the DEF tank down and checking with electric meter.

do a search here with those codes, sadly its a guess with generic code readers as the actual cause is unknown.

Anyone near you have VCDS or ODB11?

How many threads have you started on essentially the same subject???

Yes please do a search.

Also join the club - http://forums.tdiclub.com/showthread.php?t=484969

740GLE said:

do a search here with those codes, sadly its a guess with generic code readers as the actual cause is unknown.

Anyone near you have VCDS or ODB11?

Click to expand...

I have VCDS put it does not find the the necessary .ROD file.

TheGrove said:

Yes please do a search.

Also join the club - http://forums.tdiclub.com/showthread.php?t=484969

Click to expand...

I see. So the resolution by others was to have a tune performed?

That seems to be the 100% surefire way to unfix the fix, yes. Good news is, the car will run better than it ever did, and will quite likely use less fuel doing so.

I purchased Mitchell's software and now see that there is only one NOx sensor in the circuit diagram. In light of the bad readings on some Addblue control module, I guess I will purchase that and see if that takes care of most of the issues.
I can imagine that if the line heater goes bad and the ecu does not monitor it, there may be issues with how well the system operates in colder climates.

Can you check continuity of wiring?

BarryMunson said:

I purchased Mitchell's software and now see that there is only one NOx sensor in the circuit diagram. In light of the bad readings on some Addblue control module, I guess I will purchase that and see if that takes care of most of the issues.
I can imagine that if the line heater goes bad and the ecu does not monitor it, there may be issues with how well the system operates in colder climates.

Click to expand...

Good luck, VW replaced almost all of the AdBlue system along with the sensors and it never did fix the issue. In the end their solution to me was to allow me to switch from repair to buyback.

740GLE said:

Can you check continuity of wiring?

Click to expand...

Yes. I have done continuity checks on all the components on the control module along with reducing agent tank heater in with the level probes.
I saw a YouTube video on a dismantled Control module. You can see the pump motor and the wire windings. That tells me that My pump motor has windings on a stator and is bad since there is no continuity shown on the motor connector pins. The DEF injector feed line heater is also bad. (Another $180).
In my other post here I have listed the readings taken with a multimeter. I posted that separately for others to make use of if they decide to take their own measurements.

So, I have a new control module coming. I guess, since my VCDS does not see my Passat, I will have to rely on the dealership to reset the permanent OBD codes my scanner sees.