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's ...

A car’s “check engine” light is so mysterious. “Something is wrong!” it visually screams. What is wrong? Is my engine about to explode? Or did I just forget to tighten the gas cap again? The light ...