More good news for car owners

Gasoline prices aren't the only thing car owners should be smiling about. At least some car repair costs are also down. That's an additional incentive to pay close attention to the "check engine" light on your dashboard, which could signal serious problems.

The average cost of repairs prompted by the check engine light is $387 -- down 8 percent from the 10-year high in 2006, according to a study released today by auto repair website CarMD. That's partly because dealers and repair shops reduced rates during the Great Recession and haven't pushed them fully back up. In addition, hybrid cars are more common today and repairs on them are less costly than 10 years ago, bringing down the overall average.

When your check engine light goes on, don't just ignore it. The needed repair could be as minor as a $15 new gas cap. But it also could be signaling a range of more serious issues, including the need to replace the emissions-controlling catalytic converter at an average cost of $1,153.

What your exact cost will be may depend on where you live. The study revealed regional differences in both cost of repairs and what repairs were most common. Car owners in the West paid the highest average repair bill at $403, while those in the Midwest paid the lowest at $364. That reflected both a difference in auto shop and dealership labor rates and what repairs were being done most often.

For instance, the mass airflow sensor -- which helps determine the flow of fuel to the engine -- is susceptible to dust. That repair, costing an average of $382, is more common in the West and South than in other regions.

While the check engine light is linked to the car's emission-control system, it also could signal larger engine problems. "The engine and the emission-control system are so interlinked that the health of the emission-control system is a good indication of the general health of the car's engine," said Dan Edmunds, director of vehicle testing for auto website Edmunds.com.

If your check engine light comes on -- it could be in orange, yellow or amber depending on the manufacturer -- here's what to do:

  • Make sure your gas cap is on tightly. A loose gas cap can trigger the light because it tells the car's computer there's a problem in the vapor recovery system, which is part of the emission-control equipment.
  • If the light isn't just glowing but flashing, that can signal more serious trouble. It could indicate a misfire, which can overheat the catalytic converter. Faulty catalytic converters can pose a fire hazard. In this case, take the car to a dealership or auto shop as soon as you can.
  • Even if the light is just glowing, take the car in for a diagnostic reading so a mechanic can see what's wrong. Get more than one estimate if the proposed repair is costly.

If you're a do-it-yourselfer, consider getting a device that reads the car's diagnostic codes and lets you look up the repair by the codes. Then you can compare what the repair shop tells you with the information you already have.

CarMD sells a code reader for $139.95. Less expensive readers also are available at auto parts stores and on Amazon (AMZN). But the CarMD version gives you estimates of the likely cost of the repair, which you can compare with the auto shop estimate you get.

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    Jerry Edgerton, author of Car Shopping Made Easy, has been covering the car beat since Detroit companies dominated the U.S. market. The former car columnist for Money magazine and Washington correspondent for Business Week, Edgerton specializes in finding the best deals on wheels and offering advice on making your car last.