When that check engine light comes on, I freeze up. Horror stories of blown engines, locked transmissions, or shot radiators flow into my mind. More often than not, it's simply a reminder to get my oil changed. Some mechanics do not reset the meter after an oil change, so the light comes on early. Here are some other causes.

Wonder what to expect when your "check engine" light indicates troubles under the hood? Well, it turns out that the repair could be something simple costing less than $100 or something complicated costing thousands.

The most common reason is a faulty oxygen sensor, reports CarMD.com, an automotive repair website that tracks "check engine" light issues in order to create an annual Vehicle Health Index.