Can drive — fix at your convenience.
P0442 indicates the EVAP system found a small vapor leak somewhere between the gas tank and the engine. Because the leak is small, the most frequent causes are a loose or aging gas cap, a tiny crack in a hose, or a slightly leaky valve. It doesn't affect performance, but it does mean a bit of fuel vapor is escaping.
$20 – $250
Varies by vehicle and root cause.
More often than not, yes. For a small-leak code like P0442, a loose or worn gas cap is the leading cause. Tighten it until it clicks, drive a few cycles, and if the light remains, a new cap ($20-60) is the cheapest thing to try first.
Yes. It's a small vapor leak that doesn't affect how the car runs or its safety. Just address it soon so the warning light clears and you can pass an emissions test.
A gas cap is $20-60. If it turns out to be a hose or valve, expect roughly $100-250 with diagnosis and labor.
No, it's low severity. It won't harm your engine, but it lets a small amount of fuel vapor escape and will keep the check engine light on, so it's best to fix it.