I am currently driving a 2019, 2.0  tdi Superb with 77k on the clock.

The vehicle has been regularly serviced and runs perfectly. 

Every 400 miles or so the engine management light comes on with the following codes:

P2002 and P20EE.

They relate to nox emissions, bank one.

The dpf seems fine according to the vag dpf app and the differential pressures look ok.

Regen's are every 170 miles or so with town driving and complete with around d 5% soot content left.

I am thinking it may be possibly be one of these three issues:

Faulty nox sensor 

Partially blocked adblue injector,

Worst case scenario is blocked egr cooler although there are no codes showing to suggest this.

 

Has anyone else encountered these codes as I am reluctant to pay the dealer £120 for a diagnostic.

Looking through other forums regarding these codes some cars have had many parts replaced only for the codes to still be there. 

The DPF has nothing to do with NOx emissions.

these are controlled by the SCR catalyst and adblue.

 

As much as someone may be able to assist based on fault codes over the internet, it has no promises of fixing the fault. Paying for a diagnosis is not always a bad thing as they will fully look into the fault using all data and codes, tpi’s and their knowledge to find the fault.

 

that being said; there are things you can do yourself that can be checked first.

and the first thing I would be doing is checking the adblue injector nozzle is clean.

I didn't think  the dpf was at fault either.

My local VW Audi specialist told me the dpf was faulty and blocked but the readings  i've  obtained myself contradict his diagnosis. 

Will order a set of e torx spanners and check the adblue injector next.

Maybe a coincidence but started getting the error codes a couple if weeks after adding 10 litres of Redex adblue to the tank.

Edited 31 August, 20232 yr by Jon_67

The P20ee code is nox catalyst below efficiency bank 1.

P2002 code is dpf efficency below threshold bank one.

 

I have just discovered using the torque app that the post scr nox sensor readings are a constant 2,000 ppm.

I suspect that this sensor is faulty.

 

1 hour ago, Jon_67 said:

I have just discovered using the torque app that the post scr nox sensor readings are a constant 2,000 ppm.

I suspect that this sensor is faulty.

 

Or it is the max possible reading the sensor can get and it is well above that level, just something to consider. 

3 minutes ago, ApertureS said:

Or it is the max possible reading the sensor can get and it is well above that level, just something to consider. 

Yes, that's possible. 

1 hour ago, ApertureS said:

Or it is the max possible reading the sensor can get and it is well above that level, just something 

 

Does anyone know which of these sensors is the nox bank one  sensor 2. 

The front or the rear one?

 

2 hours ago, Jon_67 said:

Does anyone know which of these sensors is the nox bank one  sensor 2. 

The front or the rear one?

 

Of the top of my head I don’t sorry.

But the way to tell is if you follow the wires. One will go to a plug, the other will go to a small box (3inch by 2inch roughly) which then has a plug going into it.

 

the one with the additional box is the NOx sensor.

1 minute ago, ApertureS said:

Of the top of my head I don’t sorry.

But the way to tell is if you follow the wires. One will go to a plug, the other will go to a small box (3inch by 2inch roughly) which then has a plug going into it.

 

the one with the additional box is the NOx sensor.

That's the rear one then that's the nox sensor.  It's attached to a connector and small electronics box on the wing just below the battery. 

Thanks. 

Hi, I drive a 2018 Skoda Superb 3 with a 2.0TDI DFHA engine and DQ381 transmission, and I am encountering the same problem. Periodically, I'm getting the same error, P20EE. I have started to investigate this issue and can mention the following things:

1. I tried to have a diagnostic performed at my local official dealer. The dealer checked the errors and stated that this is a general error and does not point to an exact problem. Additionally, the dealer visually inspected the AdBlue nozzle and found no issues. They also checked the AdBlue nozzle revision and confirmed that it is from the latest version and has no problems like older versions.

2. I had a diagnostic done at my favorite VAG Service, and they also mentioned that this is a global error and it is difficult to identify the main cause. They suggested that it may be caused by the poor quality of AdBlue and Diesel.

3. I use only original Skoda AdBlue and ensure to refuel it every time it is needed.

4. I attempted to check each Diesel station in our country to find differences between them. During these tests, I found that I'm getting this error from all the stations, but the interval between the error occurrences differs. I can suppose that diesel quality is also a factor. During my vacation in Europe, I tried to refuel only at premium stations. In 4k km, I got this error only one time, whereas on my local stations, I get it every 1k km.

5. I also noticed that this error appears when I'm driving uphill at low revs (for example, on cruise control). However, now I have observed that it appears on different roads and driving conditions as well.

6. While checking other forums, I found that it may be a software problem, and the dealer admitted to this possibility. In this case, an ECU update may solve the problem.

I am still driving with this problem. I think I will try to update the ECU version to the latest one and check if the error continues to appear. In this case, I will turn off AdBlue, and that's all.

Turned out to be soot partially blocking the egr cooler as suspected. It was replaced with a genuine new one and new egr valve at a  cost of £1120. The code has not reappeared since. P2002 code has gone and also the odd appearance of the P20EE code that sometimes appeared at the same time.

Will be using dpf cleaning additive every few months from now on to try and avoid this issue again.

Edited 28 October, 20232 yr by Jon_67

Hello!

I have this same problem. Error message P20EE00 – SCR NOx Catalyst Efficiency Below Threshold Bank 1 Catalyst 1 comes up at absolutely random times. The engine light comes on. The car drives fine, so the error does not inhibit driving. I clear the error and then there is silence for the next few weeks/months until the engine light comes on again at random times.

If I'm not wrong then the code for NOx sensor is: 04L907807ED - OEM costs 600 € (lol)

1. I thought I would take this error removal on the agenda and first it seems reasonable to go to a workshop where the machine would be lifted up and checked if the adblue injector nozzle is clean.

2. If it's clean then I would buy new NOx sensor (not the OEM)

Should the error be active (engine light ON) when go to the workshop ?

Can anyone recommend a supplier for a NOX Sensor 1 and after replacement is there any reconfiguration required?

On 06/09/2023 at 11:04, RWW said:

Hi, I drive a 2018 Skoda Superb 3 with a 2.0TDI DFHA engine and DQ381 transmission, and I am encountering the same problem. Periodically, I'm getting the same error, P20EE. I have started to investigate this issue and can mention the following things:

1. I tried to have a diagnostic performed at my local official dealer. The dealer checked the errors and stated that this is a general error and does not point to an exact problem. Additionally, the dealer visually inspected the AdBlue nozzle and found no issues. They also checked the AdBlue nozzle revision and confirmed that it is from the latest version and has no problems like older versions.

2. I had a diagnostic done at my favorite VAG Service, and they also mentioned that this is a global error and it is difficult to identify the main cause. They suggested that it may be caused by the poor quality of AdBlue and Diesel.

3. I use only original Skoda AdBlue and ensure to refuel it every time it is needed.

4. I attempted to check each Diesel station in our country to find differences between them. During these tests, I found that I'm getting this error from all the stations, but the interval between the error occurrences differs. I can suppose that diesel quality is also a factor. During my vacation in Europe, I tried to refuel only at premium stations. In 4k km, I got this error only one time, whereas on my local stations, I get it every 1k km.

5. I also noticed that this error appears when I'm driving uphill at low revs (for example, on cruise control). However, now I have observed that it appears on different roads and driving conditions as well.

6. While checking other forums, I found that it may be a software problem, and the dealer admitted to this possibility. In this case, an ECU update may solve the problem.

I am still driving with this problem. I think I will try to update the ECU version to the latest one and check if the error continues to appear. In this case, I will turn off AdBlue, and that's all.

@RWW

Hi, did you fix this problem?

Because I have same car, same problem :-(