P0442: Evaporative Emission System Small Leak

P0442 means a small leak in the EVAP system that contains fuel vapors. The most common — and simplest — cause is a loose fuel cap.

Symptoms

Usually no driving symptoms, just a check engine light. Sometimes a faint fuel smell.

A loose or damaged fuel cap (most likely), a cracked EVAP hose, or a faulty purge/vent valve.

Tighten the fuel cap firmly (until it clicks); if the code returns, check hoses and valves. Clear the code via OBD2 after the fix.

Yes — P0442 does not affect performance or safety, but it slightly raises emissions and keeps the light on.

It may need several drive cycles to clear, or clear it via OBD2; if it returns the leak is elsewhere.