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SMH! Loose Fuel Cap Is the No. 4 Most Common Car Repair

April is — among many things — Car Care Awareness Month and CarMD has released its latest Vehicle Health Index. The Vehicle Health Index breaks down — get it!? I'm sorry —  the most common car repairs resulting from a check-engine-light alert in 2017 while also providing information on the most and least expensive repairs, additional repair frequency data and repair cost data nationwide and by region. Think of CarMD as WebMD for your car — without the panic-inducing doomsday diagnoses.

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Here are the top 10 most common check engine-light-elicited repairs and their average costs for parts and labor combined:

10. Replace thermostat, $225.40

9. Replace fuel injector, $447.03

8. Replace evaporative emissions purge solenoid, $151.33

7. Replace ignition coils, $217.69

6. Replace mass air-flow sensor, $340.87

5. Replace evaporative emissions purge control valve, $146.55

4. Inspect for loose fuel cap and tighten or replace as necessary, $26

3. Replace catalytic converter with new original equipment catalytic converter, $1,271.01

2. Replace ignition coil and spark plugs, $367.56

1. Replace oxygen sensor, $238.29

The good news is that 2017 repair costs were down more than 10 percent from 2016 thanks to a reduction in labor and parts costs; the bad news is that the average repair cost is $357. That's a strong argument for spending a little now so you don't have to spend a lot later.

The most expensive repair? Engine replacement, at an average cost of $7,050 for parts and labor. The least expensive? "Inspect for loose fuel cap and tighten or replace as necessary." That will cost you $26 — and probably some dignity.

You can find the rest of the report from CarMD here. If your car the needs some TLC, check out's Service & Repair to find your local dealer.'s Editorial department is your source for automotive news and reviews. In line with's long-standing ethics policy, editors and reviewers don't accept gifts or free trips from automakers. The Editorial department is independent of's advertising, sales and sponsored content departments.