P0442 on a 2017 Ford Focus Bev

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 2017 Ford Focus Bev

Ranked from 842 NHTSA owner complaints filed for this vehicle.

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1
Canister purge valve (CPV) failure
Medium severity
By far the dominant pattern in this batch: eleven separate owners report a failed/failing canister purge valve, most throwing code P1450 ('unable to bleed up fuel tank vacuum') after fueling, with stalling, hard starts, and stumbling at low speed.
Reported in 11 NHTSA complaints
Parts:purge valve
2
Fuel tank/filler-neck deformation (recall 19S22-related)
Medium severity
Several owners tie their EVAP leak/purge symptoms to Ford recall 19S22 for fuel tank deformation, which can create a leak path in the tank/filler-neck area that also disrupts normal purge/vent operation.
Reported in 3 NHTSA complaints
3
Loose or damaged gas cap
Low severity
Always worth ruling out first since it's the simplest and cheapest cause of a small EVAP leak.
Common cause
Parts:fuel filler cap
4
Cracked or perished EVAP hose/line
Medium severity
Rubber EVAP lines dry out and crack with age/heat.
Common cause
Parts:EVAP hose
5
Charcoal (EVAP) canister crack or saturation
Medium severity
A cracked housing or fuel-saturated canister can't hold vacuum during the self-test.
Common cause
Parts:EVAP canister
6
Vent valve/solenoid stuck open
Medium severity
The vent valve must seal to atmosphere for the leak test to pass; a stuck-open valve reads as a leak.
Common cause
Parts:EVAP vent valve
7
Fuel tank pressure (FTP) sensor fault
Low severity
A drifting FTP sensor can report a leak even when the EVAP system is physically sealed.
Common cause
Parts:fuel tank pressure sensor

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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