Engine light came on when I pulled in the driveway yesterday. I've driven it a bit, turned the engine off/on. Still there. Everything seems fine other than the silly light. Anybody had one turn off by itself? I don't want to leave my car at the dealership for this if it might go away on it's own.

Maybe Autozone will run a free diagnosis so I will at least know what the code is.

 

Did you tighten the gas cap? I was told by the dealer that if there is air suck into the gas tank, the engine light will come on.

 

How long have you had the supercharger? My guess is that it may possibly be related to this. If it was stock - different story. The gas cap thing is also a possibility - Not much info to help at this time though. Keep us posted.

 

Did you pull codes?

 

I take it you don't have a tuner. If you anyone that does, they can pull the code and clear it. If the light stays on for a couple of days, that means that the computer has seen the issue more than once. If it detects it only one time, the light will go out after a while. See if a friend has a handheld tuner and can pull the code for you.

 

I did tighten my gas cap yesterday. No help so far, but I'm gonna give it a little more time. I was also told at the dealership that leaving the key or engine on (to listen to the radio or keep warm) while filling up can cause this.

I don't know anyone with a tuner, but I think Autozone pull the code for free. I had them do it on my wife's car when her O2 sensor went out. I'm sure they have something there I need to buy anyway.

 

I have a high flow catted X pipe from SLP and I've had the CEL come on a couple of times. It goes out after a couple of days (or has so far anyway). If it continues I'll probably get the device that "fools" the computer into believing that "all is well" with the O2 sensors. I don't have an inspection for another 16 months though.

 

I'd recommend finding out what the code is in case it's something that needs to be fixed. If you just want the light to go off, disconnect the battery cable, wait a little while, then re-connect it. That will clear it until the computer sees it again. Like I said at first though, best thing is to find out what the code is and correct it.

 

Went to Autozone and it was a P0456 which is a small amount of air in the evaporator emission sytem or some such. If it doesn't go away by itself, I'll disconnect the battery, which I would rather not do because I don't want to arouse suscpition with the dealership that I'm covering something up.

 

Mines pulled that very same code along with some others.. (all occured within 2 months)
P0456: Evaporative Emissions leak detected (very small leak)
P0121 : Throttle/Pedal Positon sensor A Circuit
P0741 : Torque converter clutch solonoid circuit (stuck off)
P0340 : Camshaft position sensor A Circuit (bank 1 or single sensor)

my car only has 5000 miles on it... and i had it for a year... just recently it started giving me trouble.. I love the car, but i hate bringing it in everytime.. I truely will stick to my car, my dealership usually takes good care of me.. oh and the code for the gas cap loose CEL is P0457 ... I wish you the best of luck with your mustang...