Recently I have a strange rattling noise coming from turbocharger when I let off accelerator in 1st gear or neutral. I have heard adjusting the preload on wastegate actuator can fix this. (3 turns or 3mm) should do it.

Of course, if I do this, this will mean that my turbocharger will have more boost pressure, so my question is:

Will I have to get a tune or remap or any changes to boost control unit? (if there is one?)

My car is:
Fiat Punto Evo Sporting 2011 1.4 Multiair turbo

Thanks