99 F150 rough idle; SES light

OK, my wife just brought my 99 F150 home and said it was running rough, had no power and the SES light is on. She fueled it up this morning, and put about 20 miles on it. All was fine when she parked it, but when she left this evening, she said it ran rough. On the road (45mph), the SES light started flashing (fast flash). Then stayed on. Checked the fuel cap, plug wires and vacuum lines for anything loose. All checked out. Gonna get the codes off it tomorrow. Was wondering if anybody could give me a head start on it? bad fuel? filter? I've never had a problem with this truck...damn, after typing all that I had to put my shoes on and drive it. Feels like its missing on a couple cylinders. Thanks for any help.

It is relatively common for the Coil On Plug modules to fail from moisture contamination.

The good thing is that on these trucks the codes almost always tell you exactly where to look for the problem, once you get them read.

Did I mention that AutoZone will read codes for free?

The code came up 0307, misfire #7 cylinder...had a bad plug. Did a major tune up and it's runnin great again. Thanks for the help.