That dreaded check engine light doesn’t have to mean panic—or expensive guesswork. With the right know‑how and tools, you can turn those cryptic OBD‑II codes into clear clues about what’s wrong.

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 ...