P20EE Error Message

[Sykoaj]

Hi all,

I need some assistance, i have the engine light on with an error code of P20EE, i have deleted it a few times but keeps coming back so i'm assuming I have an issue. The message seems to relate to the Catalyst, however the car performs fine, i did an omissions test which came back as 0, no funny smells, no noises, car seems fine, drives and accelerates fine. However i have this message. Previously i had the error message to do with the Nox sensor about 8 months ago but seemed to disappear on its own so not sure if its the Nox sensor or the Cat. Need advice as my local garage is struggling to know what option to go with. New Cat or Nox sensor. Car is 2017 GLC 350d which has done 104,000 miles.

Thanks

 

[MSG2004]

Hello. I recall a faulty cat on a car I bought a brand new about 25 yrs ago, V6 Mondeo Ghia - you only got a years warranty - the car was about 3 years old and about 22k miles - I started to note initially a rotten egg stench at times as I drove around and then within a few weeks of that if I recall well, the car felt clogged up ie poor acceleration but no EML. Took the car to Fords, and they said it was the cat - can't recall exactly but paid a heft 600 quid all those years ago - did the trick

Nox senor fault on my Gle which I've had from new at just over 3 years old got EML, car drove ok at slow speeds but went into limp mode at 50-ish - Mobilio diagnosed Nox fault on one sensor and it was replaced by MB

 

[Sykoaj]

Hello. I recall a faulty cat on a car I bought a brand new about 25 yrs ago, V6 Mondeo Ghia - you only got a years warranty - the car was about 3 years old and about 22k miles - I started to note initially a rotten egg stench at times as I drove around and then within a few weeks of that if I recall well, the car felt clogged up ie poor acceleration but no EML. Took the car to Fords, and they said it was the cat - can't recall exactly but paid a heft 600 quid all those years ago - did the trick

Nox senor fault on my Gle which I've had from new at just over 3 years old got EML, car drove ok at slow speeds but went into limp mode at 50-ish - Mobilio diagnosed Nox fault on one sensor and it was replaced by MB

This is my problem, I have no issues, apart from the EML been on. Drove over 100 miles on the weekend without any issues. The adblue isn’t draining down fast which apparently is a sign of a bad cat. No limp mode no reduced acceleration. No rotten egg smell! I’m just stumped and so is my mechanic.