Did they check or clean the fuel injection system? That sets off the check engine light until it's reset.

Also, make sure your gas cap is on tightly. If it isn't, tighten it and the light might go away after a few more engine startups.

I hate the check engine light, it's the most uniformative indicator ever invented.

What kind of car? You can take it to the nearest autozone, and they will scan the error codes for free.

Are the temperature and oil pressure ok?

GD is right, a loose fuel cap will trip the light. On newer cars, for emissions, they will pressurize the fuel tank to detect a leak. A loose fuel cap will look like a leak.

I don't know. I will have to ask them. They're a new mechanic to me and at this moment, I miss my car dealership in VA.

As someone who doesn't know much about car repair, I always panic when I see the damn check engine light. It's my auto-response of abject panic that it will be a $1000 bill.

It's a 1998 Buick Le Sabre (yes, a lil ol lady car, what about it?)

Temp and oil pressure fine, I was watching the whole drive into work. I gassed the car when I got to the office, so the gas cap is tight.

Autozone, great tip, thanks! I will see if there is one nearby.

Don't worry, it rarely is. Usually, the mechanic just did something that depressurized the fuel system somewhere, tripping the sensor. If it doesn't got away within a couple days, bring it in. Checking the error code is a quick and easy process.

Well, thanks for the reassurance. I just called the shop and they told me to bring it in and they'd check it. You'd think this would have shown up yesterday when I was driving home? Not sitting on the street overnight.

Gotta say, I give you major :snap: for getting out there any playing. Good for you!

The measurements that trigger the check engine light (well, one of the measurements, there's a whole litany of conditions that trigger it) are averages of readings taken each time you start your car. So it takes a start-up or two for the light to trigger if, say, your gas cap is loose, and it takes a start-up or two for it to go away once you fix the problem (unless someone goes in and manually resets it).

Okay, this makes total sense. Just further illustrates how little I really know about car maintenance. But, that's what I pay the mechanic for. All I can handle is making sure I change the oil every 3k miles and check the tires. Leave them to check the fluids, belts and everything else.

We had a check engine light come on during our drive home from Disneyland last month. It started blinking and we noticed the enging misfiring (in Weed of all places) but the owner's manual said to just keep driving and have it looked at when we got somewhere that we could. It also said it has a triple something that resets the light after it has been started and not detected the problem 3 times. It could be that you just haven't hit your magic number. We figured the problem was probably bad gas though it didn't start acting funny until we were at a half a tank.

For those that don't know, there's NOTHING in Weed ;)