A6 C7 2.0 tdi 190 hp, check engine light on

[johnydriver]

Hello
Help me please with a problem.
Car: A6 c7 Avant 2.0 tdi 190 hp. (CNHA)

Problem:
After a bad gas station (filled with diesel 55), next day i found a bad smell from the exhaust and very little GRAY smoke... AND check engine light on (not flashing). (NO POWER LOSE, and very stable engine rotations)
>>> After 100 miles of driving i went to the service and they connected a tester to check for errors...
It was only 1 error on the DPF filter, it wasn't full (regenerations are every 300-400 miles) but they said it will need to be manually cleaned, they told me to come next day. And i went for a drive for 200 miles)
>>> Next day i came to the service and before starting DPF cleaning they connected a tester once again, and surprise, there were NO ERROR on DPF filter, but there was an error on AdBlue PUMP...
They told me to change the adblue pump, i said no and went home...
>>> I burned all the fuel from the bad gas station and filled with (what i think it's a good station, but with diesel 51 octane), I changed AIR filter and Fuel filter, drove 50-60 miles and Check engine light was GONE... I was super happy... Drove about 150 miles and check engine light was on again...

>>> Went back to the service and checked for errors, surprise, again the error on DPF filter...
>>> We started a FORCED regeneration and deleted the error, bad smell from the exhaust was gone and i was super happy...
>>> Next day again check engine light on

Is there a possibility that it was the oxygen sensor? Can it be broken without showing an error on it?
No one from the service know what it can be.

Please help

[johnydriver]

Hi everyone. Went today for another check for errors and i've got the error P200200, can anybody help please? thanks!

[Crasher]

The DPF is blocked and needs to be removed for proper off the car cleaning


18434 (P2002) - Particle Filter Bank 1: Malfunction

[johnydriver]

Hi Crasher. Thank you for your answer!
They said i have to change the EGR and it will be fine (just talked with them).
But i'm not sure, thats why i would like to know your opinion...
(because of bad experience in the past, of changing a lot of things which didn't need to be changed)

[Crasher]

The fault code P2002 has nothing to do with the EGR valve. Could I have the VIN?

[johnydriver]

Yeah of course, VIN: WAUZZZ4G0GN039688
They told me to change the EGR cooler

[Crasher]

The EGR cooler is mounted to the SCR/DPF assembly but I can't see why it would need replacing if there is no fault code. The SCR/DFP used on yours has been superseded but is around €2500 so we would have it professionally cleaned, I don't know if you can get that done in Germany?

[johnydriver]

Thanks for your answer
I have regenerations every 400-700km (around 400km when 50%+ city driving, and 700+ if highway), how i know there should be a regeneration every 100-200km if the DPF is full...
But i hope i'll get it done with the EGR cooler change.
I'll be back with the result in a few days