If they won the air war over Hawaii that was not going to be near enough to take Oahu. Even if they did take it they would not able to support themselves there and it was not going to win them the war. This was a lost cause for them unless the public had enough of it. If they were determined to take Hawaii at all costs they would have bled themselves dry and even if they could win it would be a pyric victory.
... Many say it was their only chance for forcing a truce.
WIthout Hawaii, the US fleet in the Pacific would be extremely difficult to handle, and any future invasion plans (Gilbert islands, Guadanlcanal, Phillipines, etc) would be out of the question.
With 550 carrier based warplanes (a conservative estimate, as the maximum loads would give room for over 650), 12 battleships and over 100 smaller ships, things could just go right for the Japanese.
A difficult endeavor, but at least they woould try to make a step in the right direction... (taking the USA out of the Pacific)