CarMD: When Check Engine Light Goes on, Check Engine, Stat!

CARS.COM - Benjamin Franklin said, "An ounce of prevention is worth a pound of cure." Well, CarMD says that when it comes to your car, prevention also is worth a whole lot of money. The Irvine, Calif.-based automotive diagnostic info provider released its 2016 Vehicle Health Index, presenting car owners with cold, hard facts about how vehicle maintenance can save them some cold, hard cash.

Related: Is El Niño Your Car's Amigo?

David Rich, CarMD technical director, said for example that a spark plug failure can snowball from $50 for a part to $400 or more for plug and ignition coil replacement. The CarMD index encourages drivers to heed their Check Engine lights to avert car trouble and maximize fuel economy.

"One of the best ways to minimize cost of ownership and help reduce unforeseen car repairs is to follow a regular maintenance program and take care of small problems as soon as you're aware of them, particularly as vehicles age," Rich said in a statement.

According to the Vehicle Health Index, the top 10 most-common car repairs related to the Check Engine light, followed by their average repair costs, are:

10. Replace evaporative-emissions purge solenoid, $184

9. Replace evaporative-emissions purge control valve, $168

8. Replace spark plug wires and spark plugs, $331

7. Replace mass airflow sensor, $382

6. Replace ignition coils, $236

5. Replace thermostat, $210

4. Tighten or replace fuel cap, $15

3. Replace ignition coils and spark plugs, $390

2. Replace catalytic converter, $1,153

1. Replace oxygen sensor, $249

CarMD's 2016 Vehicle Health Index surveyed more than a million reported repairs from Jan. 1 to Dec. 31, 2015.

Despite the potential for mounting car-repair costs, CarMD determined that the average cost to repair a Check Engine light issue in 2015 was $387. That's down 8 percent from a decade ago when it was $422.

Average costs for Check Engine issues, according to the CarMD study, were also down from 2014, with the Northeast enjoying the biggest decrease by nearly 7 percent to $391. The smallest price break was in the Midwest, where repair costs went down less than 3 percent, though the region remained the cheapest place to have your car fixed at an average cost of $365. Despite enjoying the second-biggest drop of 5 percent, the West remained the most-expensive region for Check Engine repairs at an average $403, followed by the South at $389 with a 3 percent dip.