strange "check engine" light

[AirWolf87]

For the past month or so my mustang has periodicly displayed a "Check engine light" it usualy goes when im on the highway and will stay lit for a day or two and go back off. At first i thought it was the gas cap, but taking it out and reclosing it doesnt seem to help. anyone have the same problem or ideas on what it is? i would take it to the shop but it never stays lit long enough. I dont think its serious but still makes me peranoid.

 

[streetstang03]

Go to Auto Zone and have it scanned. They will run the check for free and tell you what is making the light come on

 

[tacswa3]

A few weeks ago my light came on in my 03 GT. It had a rough idle and seemed to smooth itself out but the light stayed on. I took it to the dealer and when they took it the light was out. They scanned it anyway and cylinder 7 was misfiring. I never even felt it as I drove it. It would be a good idea to get it scanned, You never know.

 

[streetstang03]

I just remembered my check engine light would come on if I didnt turn the gas cap a good number of times on my old 97. After I added the K&N, the light would come on too, but it went away after a while. I just remember making sure I put the cap on really well and giving it a few turns just to make sure.