There's no such thing as "unnecessary changes" when electronics are involved.
You need a consistent package, not a combination of good parts that don't necessarily form a set.

So, chip, map-sensor, injectors, fuel pressure and turbo restrictor, they all have to match.
What map-sensor are you using? (2, 2.5 or 3 bar)
What restrictor is being used? (None, 38mm, 36mm, 34mm, 33mm, 32mm)
Is the car build to FIA specifications and if so, which one? (Grp A, N)