Our 2002 Ford E150, used for traveling to art festivals, recently had the Service Engine Soon light come on and begin blinking. It had a very rough idle and was sluggish when accelerating.
I changed the spark plugs and wires and it idles better now, yet the Service Engine Soon light is still on and begins blinking at about 45 mph. It also has a little shimmy (shake) over 30 mph.
Thanks,
Starving Artist