every time it gets humid out for a couple days (65-75% humidity) my check engine light comes one usualy on the last day of t he humid air and then stays on for a day or two. after driving like 100-200 miles it goes off again. this has happened like 3 or 4 times this summer. anyone know what code this might throw? every time i try to get up to aut-ho-zone it goes off and they wont do a readout if the light isnt on. got any ideas?