Well it will take longer for the catalytic converter and the O2 sensor to reach their ideal operating temperature. The engine management system may not achieve closed loop operation in a timely manner (as designed). Perhaps you will notice some minor changes in fuel efficiency, perhaps not. A more important question to have answered is "does your state perform an emissions inspection?" If so then disabling the Air Injection system is somewhat moot but then again so is the thought of disabling it IMO.