A check-engine light could be a gentle reminder or a sign of something catastrophic. We explain what a malfunction indicator light is and what you can do about it.

When your check engine light comes on, it is a warning that something is wrong with your vehicle. Here are five of the most likely causes to check for.

There are countless reasons why your check engine light could turn on, including a wiring fault, a bad oxygen sensor, or a misfire. Sometimes, the check engine light won’t reset on its own, even ...

The oxygen sensor was replaced but the 'check engine' light won't go out. Now what? Which octane fuel is best? AAA's Car Doctor has answers.

The folks at CarMD are back with their 2021 Vehicle Health Index, which documents what causes your car’s dreaded check-engine light to illuminate.

A compression test is to determine how much pressure the engine makes, and a leakdown test measures its ability to hold pressure.

I have a 99 Mustang. About a year or so ago, my check engine light (hereby known as the CEL) went on. I took it to my local shop, who charged my $75 and said they fixed it. 2 days later, it comes ...