AirBnb converted garage in San Diego?

First time home buyer about to close on a property in San Diego that has a unit in the back ideal for AirBnb. This potential income is a huge factor in our calculations for this property. The garage was converted by a licensed contractor, but if building permits were not pulled, will this impact my ability to have it be a legit AirBnb property in San Diego? Any STR owners out there who have experienced airbnb-ing in San Diego area?? Thank you!