Turbo Boost Sensor 2.0 Hdi 8V

[ESL57]

My boost sensor had been detached due to spigot being broken on it. I made an airtight repair on it and fitted it back up.

   I never noticed anything untoward with it connected or disconnected. Does it only prevent over boost? What is the real purpose of it and what is it doing?  No warnings on dash with it not connected ,although faults may have flagged if a reader is connected.

   Not sure whether to buy a new item at £40 or not?  

       Car seems to drive ok with no issues and it hits 70mph in 3rd gear with no smoke. Can't be sure it is performing as it should as I have nothing to compare it too.