Seeing your vehicle's check-engine light come on can throw a wrench in your travel plans. It can also feel a little scary: Does it mean your ride is headed for the scrapyard? Or is there a simple fix?

The world of car diagnostics has changed a lot over the last 50 years. Back in the '70s and earlier, a mechanic's most valuable diagnostic tools were usually their eyes and ears. You could figure out ...

Add Yahoo as a preferred source to see more of our stories on Google. Modern cars are technological marvels, and understanding what’s happening under the hood has never been more important—or more ...