IRVINE, Calif. — CarMD released its 2018 Vehicle Health Index of “check engine”-related car repairs, costs, and trends. The report revealed that the average cost to repair a check engine light-based incident fell 10% year-over-year in 2017. This includes a 13% dip in labor charges and an 8% reduction in parts costs based on the vehicles inspected.

The report also found that a faulty oxygen sensor, which negatively impacts fuel economy if left unrepaired, remains the most common reason vehicles experience a check engine light. CarMD further found that vehicle age impacts the type, cost, and frequency of repairs. A loose gas cap is most likely to trigger a check engine light on a 2017-MY vehicle, while faulty ignition coils are most common on 2007 vehicles.

“We are encouraged by the drop in check engine light repair costs and a lower percentage of costly catastrophic repairs, which is an indication that drivers across the country are taking car maintenance and check engine light repairs seriously and vehicles are becoming more reliable,” said David Rich, CarMD’s technical director.  

CarMD found that the average cost to repair a check engine problem in the U.S. in 2017 was $357, including parts ($216) and labor ($141), which is down 15% from its $422 high in 2006 but still 7% above the 10-year low of $334 in 2011. The five most common problems found to trigger the check engine light were oxygen sensor, ignition coil and spark plug, catalytic converter, loose or damaged fuel cap, and EVAP purge control valve. They range in cost from $26 to replace an OE gas cap to $1,271 on average for a new OE catalytic converter. Car repairs and associated costs can be affected by region, maintenance decisions of previous owners, the time it takes for the automotive technician to perform the repairs, and the vehicle’s age.

The 2018 CarMD Vehicle Health Index analyzed repairs needed on 7,167,314 in-use vehicles reported to and validated by CarMD’s network in 2017. The full Index, including the 10 most common check engine-related repairs, 10-year history of U.S. car repair costs, list of most common repairs by region, and 10 least and most expensive repairs, can be found here.