BMW (BMWG.DE) is recalling 91,800 Mini Coopers in the United States to replace a defective sensor that may prevent the front passenger seat air bag from deploying in a crash, the German automaker said on Saturday. In documents posted on the U.S. National Highway Traffic Safety Administration website, BMW said the recall of certain model year 2005 to 2008 Mini Cooper and Mini Cooper S cars is expected to being on May 1. BMW said the front passenger seat air bag may not deploy because of a defect in the occupant detection mat.