CarMD Vehicle Health Index: First jump in car repair costs in six years

Car repair costs jump 10 percent for first time in six years.

As fuel prices rise, CarMD’s Index accentuates the need for consumers to be aware that driving with the check engine light on often indicates a problem that can negatively impact fuel economy. The top five most common check engine-related problems reduce fuel economy and often escalate into more serious problems if left unrepaired.

1) The most common repair, “replace oxygen sensor” can lead to a 40 percent reduction in gas mileage if ignored, which equates to roughly $1.50 per gallon or $900 per year in extra fuel costs. A faulty O2 sensor can also lead to costly catalytic converter damage.

2) The second most common repair is “tighten or replace gas cap.” Loose or missing gas caps cost drivers time and money, triggering the check engine light and a repair shop visit, and a 0.5 percent decrease in gas mileage.

3) At no. 3, “Replace catalytic converter(s)” rose 7 percent to $1,101.44 on average. In most cases, a catalytic converter won’t fail unless a related part such as a spark plug or O2 sensor is ignored for too long. A damaged catalytic converter can result in fuel consumption loss up to 20 percent and eventually cause a vehicle to quit working altogether.

4) “Replace ignition coil(s) and spark plug(s)” costs increased nearly 7 percent from $296.87 in 2011 to $316.58 in 2012. As the fourth most common repair, Ignition coils often fail due to bad spark plugs resulting in the replacement of both parts. They can also decrease fuel economy by up to 20 percent, costing drivers an extra $450 per year extra at the pump given today’s gas prices.

5) The small but mighty spark plug returns to the top 5 list this year. The average cost to replace spark plugs and wires jumped nearly 9 percent this year. Ignore a spark plug and risk ignition coil and eventual catalytic converter damage, as well as roughly a 2 percent reduction in fuel economy.
CarMD’s free Vehicle Health ScoreCard tool, available at, helps consumers gauge their vehicle’s health, and gain access to the most common repairs and related costs for their specific vehicle.
Beginning in 1996, the government mandated on-board diagnostics (OBD2) for all foreign and domestic cars, light trucks, minivans, SUVs and now hybrids sold in the U.S. This technology detects malfunctions, sets a diagnostic trouble code (DTC) and turns on the check engine light if a problem is detected. The system is currently installed on about 85 percent of vehicles nationwide. CarMD’s network of Automotive Service Excellence (ASE)-certified technicians has built the largest, most up-to-date-database of DTCs, expert fixes and repair costs. This database, from which CarMD draws its Vehicle Health Index, adds and validates more than 500 new repairs daily. It is released each April in conjunction with National Car Care Awareness Month to provide vehicle owners and the industry with a comprehensive and independent report on vehicle repair trends. This 2013 Index statistically analyzes more than 161,000 repairs. For more information, including the complete Index, methodology and archived data, visit

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