Mazda North American Operations (Mazda) is recalling certain 2010-2011 Mazda RX-8 vehicles that were previously recalled under recall 18V-716 but have not yet been repaired. These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the passenger frontal air bag, these inflators may explode due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.