Hi , my stang stall at idle and idle rough. I've clean my IAC and my MAF. Mods are Airaid air intake, Accufab throttle body with EGR deleted, 2.5" catless system exhaust with bassani x-pipes, and Sct tuner. My car also misfires randomly on all cylinders but show no CEL. Spark plugs are white as snow. It looks like it is running lean. Could it be my IAC that is dead? Or a bad tune ? Thanks