Few things can be more alarming to a driver than when their check engine light comes on. While it can be indicative of a very simple and easy-to-fix problem, other times it could be highlighting a serious, and costly, issue.

One of the most common reasons that your check engine light has turned on is an oxygen sensor that is not working properly. According to The Associated Press, the sensor is relatively important because it keeps an eye on how much unburned oxygen is in the exhaust, which in turn keeps the car's computer up to speed on how much fuel is in the tank. If it's not working properly, the issue could take its toll on the vehicle's gas mileage.

Among the most serious issues that the light could be indicative of is a broken catalytic converter. This component is used to turn harmful gases into less damaging substances, and often uses expensive metals to do so. As a result, the average cost of repairing one can be around $2,000.

Though they may not be as serious as a broken catalytic converter, misfiring spark plugs are another significant problem that the check engine light could be warning you about. According to the AP, this malfunction might seem small but its effect can be felt everywhere from fuel economy to engine power, and may actually damage your catalytic converter in the long run.

The best way to avoid some of the most serious issues associated with the check engine light is to make sure you're on top of regular maintenance. New Jersey State Auto Auction's Total Car Care center provides the general public with a great resource to keep their cars running smoothly. With a stable of talented mechanics, the center offers everything from repair to general upkeep.