When a vehicle’s check engine light comes on, drivers in California now pay the most ($435) on average, while vehicle owners in Michigan pay the least ($354) to have it fixed, according to CarMD, which analyzed data from more than 1 million vehicles needing repairs in 2015. Rounding out the five most expensive states for auto repairs are Wyoming (no. 2), Maryland (no. 3), North Dakota (no. 4) and New Jersey (no. 5). After Michigan, the most affordable states for car repairs are Indiana (no. 50), Ohio (no. 49), Wisconsin (no. 48) and Iowa (no. 47).

• U.S. Average: The average cost for check engine light-related repairs in the U.S. in 2015 was $387. 31. Florida is closest to the U.S. average at $387.37, which is just 6 cents from the national mean.
• Labor and Parts Costs: Michigan vehicle owners paid the least for both labor ($150) and parts ($203) on average. Drivers in Wyoming paid the most for labor ($175) on average and vehicle owners in Vermont paid the least for parts ($131). Several factors contribute to average parts and labor costs, including vehicle make and age, parts availability, difficulty of repair and hourly labor rates.
• Repair Costs Vary by State: The same repair can vary in cost from state to state. To replace a car’s ignition coil(s) and spark (plugs), the average cost is $435 in Washington, whereas the same type of repair in Vermont costs 16 percent less at $364 on average. A catalytic converter replacement costs on average $1,226 in New Hampshire, but only $891 in Hawaii. And the average cost for parts and labor to replace a car’s oxygen sensor(s) in 2015 varied from a low of $216 in Wyoming to a high of $290 in Delaware.
• It Pays to Address Small Problems: The least expensive states tend to have a higher percentage of repairs that can be addressed in a matter of minutes versus major parts replacements that require days in the shop. For example, loose gas cap-related problems happened nearly twice as much in Wisconsin as in North Dakota. CarMD encourages vehicle owners to have check engine problems diagnosed early because in many cases it is a common repair like an oxygen sensor or simple, affordable fix like a loose gas cap causing the problem. Addressing warning lights early helps reduce the chances of doing additional damage to your vehicle.

CarMD’s ranking of the five states/districts with the highest car repair costs in 2015:

CarMD ranking of the five states/districts with the lowest car repair costs in 2015:

State-by-State Ranking of Average Check Engine Light Car Repair Costs – 2015
(Source: CarMD.com Corp., CarMD® Vehicle Health Index™)