P0401 code reoccurs every few hundred miles but clears itself after one day.

[BENZE220AMG]

Greetings, everyone. I need guidance on my 2015 Mercedes CLA 220d, which has 65,000 km. Three months ago, I had the intake manifold fixed at my local service. The day after it was replaced I had P0401 code pop up so went it straight back to the shop who stated it was probably due to not resetting the egr valve. They stated they reset the egr and erased the P0401 code.
500 miles later the code came back on so brought it back for additional testing. A smoke test was conducted along with a brief inspection of the visible hoover hoses. Everything seemed satisfactory, hence the code was reset once again.
700 miles later the code came back on and again was reset by the garage claiming they didn’t know what it might be. They stated they could replace specific items like egr etc but it would be guess work and a process of elimination.
Basically I need to know Whether I can continue on driving it like this since it only comes on for like 20 miles a time every few hundred miles and also does anybody have any thoughts what it may be?
I consulted my Mercedes expert, who indicated that they could need to disassemble the system, perhaps requiring the replacement of the EGR and cooler. My fear is that this might result in costs up to thousands.
Any assistance is appreciated.
Thank you.

[SD1too]

Try removing the egr out and clean it. Mr muscle oven cleanser works a great.

[BENZE220AMG]

Thank you for your response. Another issue I failed to add before I had the intake manifold fixed one garage informed me I also had an egr code aswell. Not sure which code it was but I presume may have been the same

[Needsnewtyres2]

Have you enquired with the Mercedes expert on the cost? That would appear to be better than guessing your self or asking local garages who may be wonderful individuals but not MB experts

[stevenkeyte]

We just saw a similar code on one of our children's SUV, which is not a Mercedes.
Our son ordered a component from eBay, which was incompatible. He then attempted to purchase from Euro Car Parts, but it too would not fit. The dealer's price was a substantial £170, if I recall correctly, compared to £50 to £80.
The automobile remained operable, but its use diminished in favour of another vehicle.
Over the weekend, as @OneForTheRoad said, our son cleaned the valve, which is readily accessible on his vehicle. It has been 3 to 4 weeks, and the car is functioning at 100%.
There was a black substance present, which is a recognised issue associated with his automobile model. Nonetheless, there may sometimes be an alternative issue contributing to the accumulation of filth, among other substances.
Experiment and assess your progress.

[BENZE220AMG]

My vehicle is scheduled in at the merc experts next Monday and they’ve said they don’t want to terrify me but they had a girl in lately and it cost her £3000 as they replaced EGR, cooler and manifold… clearly my manifolds been updated. They stated the would strip everything down and see what’s wrong but he said they’d rather replace things that appear a little dodgey rather than me having to come back again with identical issue

[BENZE220AMG]

I sought guidance here prior to seeing professionals.

[nickoyster4]

Please check on youtube video