On same engine had a similar issue and symptoms.
Transpired to be turbo boost pipe not being seated correctly by technician after a service. Error code indicated air mass issue.
Acid ratio test for wheel balancing is driving the car on a private road at 70mph plus.
If no vibration from 60mph plus onwards then all good imo.
If no vibration then all is well and do not stress until next tyre change. Unless you have a decent tyre fitter I know and fully understand...
Sorry to hearing that new boost sensor did not fix your fault.
As others have said get a decent auto electrician to confirm and diagnose.
Has the technician refunded you back your money for fitting new boost sensor?
Not sure as I am not an expert but if overboosting then I am guessing it is possible with extra load on the worn seals but also get him to replace all of the relevant gaskets/seals for the turbo feed pipes.
The seals are relatively cheap.
Thanks for replying back.
It appears that apart from a couple of companies I found they will not do GAP if over 365 days. No joy with specialist brokers either.
Lesson learnt for future as with standard insurance in first 12months it was instant replacement. Car is just a few days over...
A quick question regarding GAP insurance.
Is there any company out there that will provide cover for a new policy if taken delivery of the vehicle just after 365 days?
Many providers will not provide cover if not taken policy out in the first 12 months of ownership I am finding.
Sounds like defective siren for the alarm.
If so, I think on W218 it is located in the front near side wheel arch like many other models.
You could disable the alarm from sounding by simply disconnecting the plug for the siren by removing wheel arch lining for access until you get replacement...