In many cases, it's safe to keep driving when a solid check engine light turns on, but it's a sign to get the car diagnosed as soon as possible.

At a time when vehicle diagnostics can demand a computer science degree, being able to get some insight into your engine health with nothing but a rag and a bit of know-how can be downright refreshing ...

Tracking down the cause of the check engine light on my BMW—scanning codes, troubleshooting, and repairs.