1994 Ford Aerostar van with an intermittent check engine light.

[jimpierce]

Just hoping to get an idea here. Before spending the money on a diagnostic. A couple weeks ago I went on a bit of a road trip and when I got to my first destination (about 120 miles) when I parked, I noticed the engine was idling very high. I shut off the engine and it stopped as usual.
She started right back up and off we went. About 10 minutes or so into the trip (on the freeway) the check engine light came on. Engine is running fine Oil good. Water good. I don't know.
Got to my next destination, shut off the engine, ok.
Started, all was ok and no light on. It was about 20 minutes or so on a back road back to the freeway. No light.
5 or 10 minutes on the freeway check engine light came on for a minute. Went off for a minute. Came back on and stayed on until I got home. Stopped at the gas station. Light went out.
The light only seems to come on when I am on the freeway. Once it stays on, it doesn't go off until I shut the engine off. It doesn't come on at all when driving around town or even longish trips on city streets.

Guess I better tll you what I drive?
'94 Ford Aerostar. Best work truck I ever had!

 

[BrooklynBay]

I once had an intermittent check engine light issue with my 1995 van when the oxygen sensor was bad. Don't disconnect the battery or replace any parts until you find out what the code numbers are.

 

[Jose A.]

stop at any Autozone store and get the codes read free

 

[Turdle]

Our 93 did this and without reading codes I replaced the 02 sensor, never saw the light again.

I actually phoned a radio car repair talk show and they suggested it. I think it went at about 101k miles.

 

[jimpierce]

Our 93 did this and without reading codes I replaced the 02 sensor, never saw the light again.

I actually phoned a radio car repair talk show and they suggested it. I think it went at about 101k miles.

that is real close to my mileage! I'll go get the codes.
Thanks!!