Today while driving across town to my Mustang Clubs annual hog roast, I looked down to notice my check engine light on. I am on the interstate and going approx. 70 mph. When I left to come home it was still on when I started the car. Decided to take the long way home going through town and sitting at a stop light downtown I look down and notice it is off. I do have an Actron OBD 2 code scanner but I guess it would be a futile effort to hook it up now. It is a 2006 GT with auto trans, stock tune and 11,750 miles. Does anyone have any thoughts or ideas?

 

Gas cap? Did you fill up today? Gas caps are a classic simple cause of CEL. Outside of that... anyones guess.

 

Thats the only time I've ever gotten a CEL.

 

I filled up Tues. the 5th and I always turn the cap until I hear it ratchet. Good idea though. The only thing different I can think of is all summer I have been using the AC everyday. This week it has been somewhat cooler and I have been enjoying the weather with the windows down. When I came home it was 86 out and I turned the air back on. I really don't see how this could affect it. Does the cars memory store past codes and if so could I access it or would that be something only a dealer can retrieve?

 

You can still hook up the code scanner just to check.

 

it has happened to my 08 to. It is one of those things that even though it bugs me i let it go because it is anyones guess to what set it off. But it is off now so just act like your car fixed itself

 

It's not that uncommon to have a parameter go out-of-spec long enough to throw a CEL and return to normal, allowing the CEL to clear over time or mileage. I wouldn't sweat it but if you can pull it, the code should still be in memory just to see what it was.

 

I would take it in asap.
Your car could very easily go into fail safe mode and then driving around will not be an option.

 

My old car would throw a code about it running lean. The light would turn on and off but the code always stayed in the memory. Plug it in and check it out.

 

It has been a while since I made my original post. I bought the scanner originally to sort through some issues with the CEL on my '96 T-Bird DD and hadn't thought about or needed it for the last few years. I spent the next two days tearing the house apart looking for the scanner and it was no where to be found. I am a very organized person and usually don't misplace things. I rarely loan my tools except to really close friends, long story short I start making some phone calls and found it. I plugged it in this afternoon and found the code P 0456. It said "EVAP Emission Control System Leak Very Small" My CEL is still off and thought I'd ask your guys opinion if this is something I should have checked by the dealer. Being out of warranty as far as the 3/36 goes but thinking might be covered by the 5/60 powertrain warranty. I had called the dealer when I couldn't find my scanner and they wanted $79.95 to run a diagnostic only, so I didn't pursue the matter with them any further. The car only has 12,200 miles.