I have a 2004 Tribute with 94,000 miles on it. Lately whenever it rains it runs very rough, seems to misfire, check engine light comes on. I checked some posts about this and proceeded to change all the coils and put in new spark plugs. Check engine light cleared on its own, ran better until... it rained! Doing the same thing again. Runs horrible after a rain, sometimes the check engine light blinks, then it will remain solid. What else should I do? Dealer wants $130 to just hook it up and diagnose it.