Idles very low almost to stalling point

Your fuel mixture is not rich enough. Have your mechanic make this simple adjustment.

Air fuel ratio is done by the computer not a mechanic. Its not adjustable unless the computer is reprogramed and its not something that ever needs to be adjusted. Before starting it try priming your fuel system by turning the key on without starting it for 3 seconds then turn the key off for a second then turn it on for 3 seconds then off for 1 then on for 3 then attempt to start it immediately.

Could also be a sticking idle air control valve.

car stalls when idling