[The Londoner]

I've got a 330i (N53) and it has just had it's nox sensor replaced but it seems to have created a new problem.
Within 30 minutes of leaving the garage I noticed a vibration coming from the front of the car. The vibration only occured when coming to a stop and for the first few seconds of idling. It's hard to locate the exact source of the noise but it sounds like it's coming from under the car either below where I sit or further forward under the engine bay. Sounds like a low vibration noise, plus I can feel a slight vibration coming through the gearstick and steering wheel that I couldn't feel before. My first thought was that it's coming from the exhaust vibrating against the bottom of the car.

I took the car back to the garage and they checked the exhaust for any loose fixings etc but found nothing.
They now reckon they've tracked the source of the vibration/noise to the intake manifold. To try and fix the problem they reset the adaptations as they wasn't sure if they did it after fitting the new nox sensor.
I drove away and the vibration was gone. Happy days.

However, the next day it returned. And it was different, and worse. It sounded the same as it did before they reset the adaptations, but now it happens on cold start (before resetting it would only start happening after 5-10 mins of driving) and now it doesn't only happen for the first few seconds of idling when coming to a stop.... Now it continues to rumble/vibrate until I put the car in P or rev the engine or pull away.

I contacted the garage again and they say there is an ecu update available for my car so they'll install that and see if it cures the problem.

My question is.... Is this coincidence or could a new nox sensor affect the running of a car in this way?
Also, by not reseting adaptations after installing the new nox sensor and then me driving around for a few days could this cause problems/damage to the car??

Any advice welcome. Thanks.