P0442 on a 2016 Ford Fusion

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 2016 Ford Fusion

Ranked from 1,659 NHTSA owner complaints filed for this vehicle.

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1
Canister purge valve/solenoid failure
High severity
A cluster of owners report the canister purge valve repeatedly failing -- throwing the check engine light, causing rough running when fueling, and needing dealer replacement, sometimes more than once on the same vehicle.
Reported in 7 NHTSA complaints
Parts:purge valve
2
EVAP vent/blocking valve failure
Medium severity
One owner reports an 'EVAP blocking valve' failing outright and putting the vehicle into limp mode, consistent with a vent-path component that won't seal.
Reported in 1 NHTSA complaint
Parts:EVAP vent valve
3
Loose or worn gas cap
Low severity
A cap that doesn't seal fully is the most common small-leak trigger; verify it clicks and inspect the gasket before condemning other parts.
Common cause
Parts:gas cap
4
Cracked or aged EVAP hose/line
Medium severity
Small cracks or brittle connections in the EVAP hose routing produce exactly the low-flow leak this code is designed to catch.
Common cause
5
Charcoal canister crack
Medium severity
A hairline crack in the canister housing leaks vapor slowly enough to trip a small-leak code rather than a large-leak one.
Common cause
Parts:charcoal canister
6
Rusted or corroded fuel filler neck
Low severity
Surface corrosion or pinholes in the filler neck, common in salt-belt climates, create a slow leak path detectable during the EVAP monitor.
Common cause
Parts:fuel filler neck

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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