P0442 on a 2015 Ford F 150 Super Crew

P0442 means the EVAP system could not hold pressure or vacuum during a leak test, but the leak is small.

Not your vehicle? See general P0442 info.

Most common causes on the 2015 Ford F 150 Super Crew

Ranked from 1,425 NHTSA owner complaints filed for this vehicle.

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1
Capless fuel filler flap seal failure
Medium severity
This exact truck uses Ford's capless fuel filler; owners report the flap allowing air into the tank and setting EVAP small-leak/fuel-fill-door codes, requiring purge-solenoid and canister diagnosis at the dealer.
Reported in 2 NHTSA complaints
Parts:fuel filler flap seal
2
Purge valve/solenoid failure
Medium severity
A leaking purge solenoid — replaced (unsuccessfully at first) on this truck for a recurring small-leak code — lets outside air bleed into the EVAP system during the leak test.
Reported in 1 NHTSA complaint
Parts:purge valve
3
Cracked or perished EVAP hose
Medium severity
Age-hardened EVAP lines near the tank or engine bay crack and produce a small, steady leak that the monitor detects.
Common cause
Parts:EVAP hose
4
Cracked charcoal canister
Medium severity
A physically cracked canister shell is a common small-leak source, particularly with age or road-debris impact.
Common cause
Parts:charcoal canister
5
Corroded/rusted filler neck
Medium severity
Rust-through at the filler neck opens a persistent small leak path, more common in road-salt climates.
Common cause
Parts:fuel filler neck
6
Vent valve stuck closed or restricted
Medium severity
A restricted canister vent valve prevents the system from equalizing properly during the leak-check cycle, which can register as a small leak.
Common cause
Parts:vent valve

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These causes are aggregated from NHTSA owner complaints and general repair knowledge — this is not a diagnosis. P0442 on your car still needs shop confirmation before any repair.

Common symptoms

Check engine light
Fuel smell near vehicle
Usually drives normally
Hard start after fueling in some cases

What to check before replacing parts

Tighten and inspect the gas cap

Look for: A cap that doesn't click to full tightness, has a visibly cracked or flattened seal, or is simply missing is the single most common cause of a small EVAP leak — rule it out first.

Smoke-test the EVAP system

Look for: Because this is a small leak, expect only a thin wisp of smoke or a faint hiss at one spot (a hose, seam, or valve) rather than an obvious cloud — look closely and take your time.

Check purge valve sealing

Look for: A purge valve that doesn't hold vacuum when commanded closed lets a small amount of air bleed through, which the system reads as a leak during its self-test.

Inspect hoses near the tank and engine bay

Look for: Look for small cracks, soft/collapsed spots, or a hose that has pulled loose slightly at a fitting — any of these can leak just enough to trip a small-leak code without an obvious fuel smell.

Verify vent valve operation

Look for: A vent valve that doesn't seal fully when commanded closed prevents the system from holding vacuum during its self-test, which reads as a small leak even with no physical leak in the hoses.

Rather have a pro handle it? Find a vetted local mechanic.

Matching symptoms

Check Engine Light