Map sensor resolution isnt an issue !!

On weber ecus, the analog to digital converter is 8 bit.
This gives a possible 256 readings of the sensor. I.E. a value between 0 and 255.

So for a 3 bar sensor, this equates to 0.0117 bar (0.1699 psi) per bit.
This isnt that bad actually and can provide pretty accurate fuelling
if mapped correctly in the first place of course.

(figures are not exact but represent what happens)