P0442 — Evaporative Emission System Small Leak Detected

P0442 means a small leak (typically smaller than 0.040") in your EVAP system. Start with the gas cap; small leaks often come from cracked O-rings or hairline hose cracks.

Cost range: $0–$400. Severity: low. Safe to drive? Yes.

Most common causes of P0442

1. Worn gas cap O-ring — Cheapest first fix. ($0–$25)
2. Tiny EVAP hose crack — Often requires smoke test to locate. ($20–$150)
3. Leaking purge or vent valve — Valve seals fail with age. ($80–$300)

Symptoms drivers report with P0442

• CEL only