Ford is recalling about 391,000 Ranger pickups because the driver’s air bag inflators can explode with too much force and cause injuries. The recall covers trucks from the 2004 through 2006 model years in the U.S. and Canada. It comes just days after the government announced that a South Carolina man was killed when an inflator exploded in December. Joel Knight, 52, of Kershaw died when he was struck in the neck by metal shrapnel after his 2006 Ranger hit a cow in the road and struck a fence.