Lamb over rice by him and Anchemist is not long out and 4 out of 5 good.
As with all "lightly driven" multijets, the wastegate actuator on mine is crudded up and sticky. This creates a bit* of boost lag on occasion which ranges from levels of "I didn't notice at all" to "why is nothing hape...FUUUUUUU!!!".
It's a common ting and most just drive around it (see below)
HELPFULLY Fiat chose to build the entire car around the turbo so it's nice and inaccessible.
With the air box and battery out, you can just about see it.
Plan is at some point to blast it with some wd40 or non brand equivalent and lever it about a bit. This is reported to usually work wonders.