Driveable with no symptom. Try a new fuel cap first — it is the most common cause by a wide margin and the cheapest to eliminate. If that does not clear it after a few drive cycles, the system needs a smoke test; asking whether one was done is a reasonable question.
The system failed its pressure or vacuum test by an amount corresponding to a small leak — conventionally a hole of around one millimetre. The size classification is genuinely useful: it tells you roughly what you are looking for, and a one-millimetre hole is too small to hear, too small to smell, and will not be found by looking.
The fuel cap is the first thing to check, and not only because it is cheap. Its seal hardens with age and a cap that tightens normally can still leak, so a visual check is not sufficient. Beyond that, this is smoke-machine territory: introduce smoke into the sealed system and watch where it emerges. Common findings are the canister vent valve, the filler neck seal, and hoses that have gone hard where they pass near heat.
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
P0442 is the EVAP system finding a small leak — and small is the operative word. Where the large-leak code usually surrenders to the fuel cap, this one is reported for openings in...
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