Onboard diagnostics (OBD) systems have been around since the 1980s and were developed to help limit harmful automotive exhaust emissions. Between 1988 and 1995, U.S.-built vehicles came with what ...

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.

Consumer Reports explains what the check engine light means and what to do when you see it: how to tell if your car has a loose gas cap—or a serious engine problem.