Theres several causes
But nothing is easy to check
Faulty sender part of the fuel pump
Blocked breather, so it's not real full
High resistance in the wiring
But the most likely is the needle is on the shaft is in the wrong place
It can be reset.
Thought I post on here as the information on sealing rings is hard to come by Oil filters 1.2 There's two types notice the engine number of the swap over The early ones are longer, A it the diameter H is the length C is the outer diameter of the sealing ring Also notice the bypass...
www.fiatforum.com
I'd be tempted to live with it