The only geometry adjustment I know of for the 159 is to set toe at straight ahead -- it'll help with tyre wear up front.
Pressures are listed in the handbook as tyre sizes only NOT for different engines so if you have the ti and therefore 19 inch wheels 235 x 40 x 19 , it's 2.7 bar front 2.5 bar rear , for average load and speed up to 100mph --- then either full load or constant over 100 mph then 3 bar front 2.8 bar rear .
I have the 2.4 ti and not certain but believe it's heavier than the 1750tbi . I run mine at the 2.7 bar front 2.5 bar rear pressures and run the higher setting when towing my race car on the trailer.
In any event , I can't imagine the tyre walls putting up with 34 all round on such low profile !!! BUT I could be wrong ?