P0401 code every several hundred miles that goes off itself after 1 day

[lancs19]

Hi all. I need some advice, I drive a Mercedes CLA 220d (2015, 65,000 miles)
3 months ago I had my intake manifold replaced at my local garage. The day after it was replaced I had P0401 code come up so took it straight back to the garage who said it was probably due to not resetting the egr valve. They said they reset the egr and deleted the P0401 code.
500 miles later the code came back on so took it back fir more tests. It was smoke tested and a quick check of any visible vacuum hoses. All seemed fine so the code was again reset.
700 miles later the code came back on and again was reset by the garage saying they didn’t know what it could be. They said they could replace certain things like egr etc but it would be guess work and a process of elimination.
Basically I need to know Whether I can carry on driving it like this as it only comes on for like 20 miles a time every several hundred miles and also does anyone have any ideas what it could be?
I’ve been to my merc specialist and they were the same saying they could strip it down potentially having to change the egr and cooler my concern is this could end up costing into the thousands.
Any help gladly received.
Thanks

 

[OneForTheRoad]

Try taking the egr out and clean it. Mr muscle oven cleaner works a treat.

 

[lancs19]

Try taking the egr out and clean it. Mr muscle oven cleaner works a treat.

Thanks for reply. Another thing I forgot to mention before I had the intake manifold replaced one garage told me I also have an egr code also. Not sure which code it was but I guess could of been the same

 

[keith of kent]

Have you actually asked the Mercedes specialist what the cost would be? That would seem to be better than speculating your self or asking local garages who may be fine people but not MB specialists

 

[MSG2004]

We recently had a similar code on one of our children's SUV - not a merc.
Our son order a part from ebay, it did not fit, then eurocarparts it did not fit -
dealer price was heft 170 IIRC vs 50/80 quid
Car was still driveable but they did not use it as much and used another car.
Then over the weekend, as @OneForTheRoad road said,
our sone cleaned the valve, it is easily accessible on his car - its been 3/4 weeks, car is 100%
There was this black stuff on it and its a known problem on his make of car. Having said that, at times
there may be another problem causing the build-up of grime etc
Try it and see how you get on

 

[lancs19]

Have you actually asked the Mercedes specialist what the cost would be? That would seem to be better than speculating your self or asking local garages who may be fine people but not MB specialists

My car is booked in at the merc specialists next Monday and they’ve said they don’t want to scare me but they had a lady in recently and it cost her £3000 as they changed EGR, cooler and manifold… obviously my manifolds been changed. They said the would strip it down and see what’s what but he said they’d rather change things that look a bit dodgey rather than me having to come back again with same problem

 

[lancs19]

My car is booked in at the merc specialists next Monday and they’ve said they don’t want to scare me but they had a lady in recently and it cost her £3000 as they changed EGR, cooler and manifold… obviously my manifolds been changed. They said the would strip it down and see what’s what but he said they’d rather change things that look a bit dodgey rather than me having to come back again with same problem

So I thought I’d ask for advice on here before going ahead with the specialists