Having your check engine light come on can be a bit disconcerting as it could mean anything from major problems to something as simple as a gas cap not being tightly screwed on.

While the issues can vary widely, CarMD has released its annual Vehicle Health Index Make and Model Reliability Rankings which analyze check engine repairs and their related costs. This year’s study looked at over 5.6 million vehicles from the 1996 to 2018 model years which reported a check engine light coming on between October 1st, 2017 and September 30th, 2018.

According to the results of the study, Toyota vehicles were the least likely to have the check engine light come on. The automaker was followed by Acura, Hyundai, Honda and Mitsubishi.

While it’s good to have a reliable vehicle, some repairs are unavoidable. When this occurs, you’ll probably want one of the cheapest vehicles to fix. Mazda lead the study with an average check engine light repair cost of $286. It was followed by Kia ($320), Dodge ($326), Hyundai ($328) and Chrysler ($329).

The cheapest vehicles to fix were the 2017 Hyundai Tucson and Accent which had an average repair cost of $67 and $69, respectively. Other models with affordable repair costs include the 2016 Kia Rio ($70), 2014 Toyota Prius C ($83) and 2017 Mitsubishi Mirage ($84).

Unsurprisingly, the study says the “most common and affordable repair on 9 out of 10 of the most affordable vehicles is to inspect or replace a loose, damaged or missing gas cap.” This is pretty common sense stuff and owners should always double check the gas cap before heading to the dealership and paying around $70 to have them tell you you’re an idiot.

As for the most reliable vehicles, the winner is a bit of a surprise as it’s the 2016 Audi Q5. It was followed by the Subaru Crosstrek and three Honda models (CR-V, HR-V and Civic).