Nox sensor query

[Yanny]

Hi all,
I see this topic has been beaten to death and i have read through the many posts however, i have not come across the same issue i am having and it's confusing me, let me explain.

So just purchased a 2017 C220 AMG Line 4MATIC last week and the car is great (first merc owned by me but worked on many) so me being me i plugged the diagnostic in just to see if all was well and to my surprise there are a few fault codes.
I cleared all codes but 4 come up as stored and i cannot delete them. Three of them are for another post but one in particular is showing

P220E77 The heater of NOx sensor 1 (cylinder bank 1) has a
malfunction. The commanded position cannot be reached.
STORED

I have no engine light on and the car seems to be running ok apart from it seems to be a bit thirsty (44mpg on a run?)

If anyone can shed a light on the issue it would be greatly appreciated before i go back to the dealer with it,

Thanks in advance,

John.

 

[nj80]

Damn mate, I just bought my second w205 250d coupe and this time your story is the same as mine! I came here to ask if its possible to have error codes, with no engine warning light on and I see I am not alone lol the main fault code is the dreaded P229F85 The NOx sensor 2 (cylinder bank 1) has a malfunction.
would you believe the first car I bought a 2016 version had this same fault, but showed up with an error code the same day on the drive back so I returned the car as the dealer was giving me a real runaround to get the issue sorted and may have just cleared and reset. I hope someone can throw light on this as I called the company I purchased from and they basically said its not worth scanning a car if there is no fault codes and but given the low millage and ride I should get it looked at and sorted under the 3 month warranty... I messaged back you will be sorting it under sale of goods or I'll be retuning it.

 

[Yanny]

I cleared the fault with my diagnostic two weeks ago and i keep meaning to re-scan it to see if it came back, il do it tomorrow and post back here.

I mentioned it to the dealer and they said "let us know and we will get the NOX sensor mapped out for you" My reply was, the car has only done 60k so i want a new NOX sensor.

I also have two other faults with it, Steering column fault (parktronic doesn't work i think) and the steering lock doesn't work but il make separate posts about those oh and the clunky gear change at low speed and the tyre road noise and it's pants mpg, especially compared to the Q7 i part ex'd it for but apart from that i'm loving the car lol

 

[nj80]

yea too right! you dont want it mapped out and then still failing later. Hmm I wonder if it being mapped out would mean it doesnt throw an error code but would still effect the mpg adversely? apart from this car and the same model I had before it earlier this year I've only had vw and then Audis and I never had any issues lol but I cant front I do like this model from Mercedes... just not feeling these issues laying silent with no warning light. so far after clearing the codes only one minor one has returned regarding communication with a sensor

 

[rf065]

yea too right! you dont want it mapped out and then still failing later.

How can it fail if it's been mapped out?
Delete the adblue system and the car will run better than it ever has without any more Adblue or Nox sensor codes ever again.

 

[Yanny]

Sorry for the late post but i cleared the code and it hasn't returned, so far so good however, mpg around town 33 mpg on average and best on a run between 60 - 70 mph i saw best at 47 mpg. I know knocking around town dependent on traffic that could vary a lot but i would expect around 55 mpg on a run.

@rf065 The adblue is working as it should so until it fails il leave it alone, don't mind doing my bit for the environment

How exactly with the car run better having the adblue and Nox mapped out?

John.