Hellp everyone.
Am quite new to the Honda family and also this is my first car, Civic Ef sedan.

the previous owner swapped the engine.
it's a D15z9 carburated.
as far as i've searched the internet.
​​​​​all d15z9 are injections and also vtec

so my questions are:
-who mine is carburated?
-is it possible to make it an injection engine?
​​​-if not, what are the things I can do to make it fuel efficiency?