I have a 97 Aerostar. Last September, the CE light came on while on vacation. My husband checked all connections under the hood and the light had gone off when restarted. Car was fine until last week, when the light came back on again. It was off in the morning while running around, but came on in the afternoon. I then filled up with gas (had 1/4 of a tank left), replaced the air filter, and just checked all connections visually under hood. When started later after the car cooled off for a while, the CE light was off. The light stayed off and I went into for my emissions testing at the end of the week. They use only a computer hookup for code checking, and gas cap check on 96 and newer cars and light trucks. I passed. Car runs great seems no different. CE light came on again this afternoon once again. Car this time was cold, but had been run in the morning for a short while. I did all the same but the light is on still. I will check it later when the car is cold. Local area is cold (high of 15 today) and very dusty with salt dust when driving. Could these have anything to do with the light? What could it be? Apparently, the previous lights didn't leave a code seeing how the testing facility didn't obtain any when the the car was checked.

 

Don't know if you already know this or not, but Ford has a problem with the mass airflow sensor, on an aerostar, it is on the air intake tube just behind the air filter. There are two screws holding it in place, and they are tamper proof screws. getting them out can be pretty tough if you don't have the proper tool, but a shade tree method can be to file across the heads enough to get a flat head screwdriver into them. when you get this little guy out, it has a couple of springs, much like light bulb filaments. Over time these springs can become dirty or oxidized, especially if you are in dusty or salty environments. You can clean them up with carb cleaner, and see what happens. Hope this helps