I took my car in to the shop because the "check engine" light was on and found out this was simply due to my gas cap being loose. Why would that set off the warning light? – Louis in Duncan, B.C.

Without a diagnostic tool, it's challenging to determine what is wrong with your car and whether to keep driving when a solid ...

Three of the main reasons the check engine light or malfunction indicator lamp (MIL) turns on are: a loose fuel cap, issues with the ignition system, and problems with the emissions system. Many ...