the aem unit does come with the MAF hole, however you may have a cel thrown with the aem unit, and also run lean if you use there's, the better route to go is the X-factor intake, which is a midified cr-v tube, with the stock MAF housing, which has been dyno proved time and time again to be the best intake ever developed for the new Si's, give the best air fuel ratio which is etremely close to the stock ratio, while still producing the most power of any intake made to date at 14hp gained, they run about 300.00, and there is a waiting list to get one unless you try to make it yourself, which the result might not be the same, more info can be found on 8thcivic.com .