P0442 on a 2021 Ford Bronco Sport
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 2021 Ford Bronco Sport
Ranked from 665 NHTSA owner complaints filed for this vehicle.
- 1
Cracked/leaking fuel injector (recall 25V467) affecting fuel vapor system
High severityThe dominant fleet-wide defect: cracked injectors leak fuel/vapor near the intake, which can both trip EVAP monitors indirectly and coincide with the fuel odor several owners report.
Reported in 17 NHTSA complaintsParts:fuel injector - 2
Purge valve failure (stuck open)
Medium severityOne owner had an independent shop confirm a bad purge valve causing stalling/low RPM after fueling; another's own scan showed the EVAP vapor pressure and O2 current functioning incorrectly; a third's inspection found the purge valve bad alongside a fuel-soaked canister — this is documented as a known Bronco Sport issue.
Reported in 4 NHTSA complaintsParts:purge valve - 3
Charcoal canister saturated with fuel
Medium severityA deeper inspection on one vehicle found the charcoal canister completely full of fuel, a classic small-leak/over-purge symptom.
Reported in 1 NHTSA complaintParts:charcoal canister - 4
Fuel filler neck / tank vent restriction
Low severityOne owner's pump repeatedly stopped after dispensing only a fraction of a gallon — a filler-neck or vent-path restriction that also disrupts the EVAP monitor's small-leak test.
Reported in 1 NHTSA complaint - 5
Loose or worn gas cap
Low severityThe single most common trigger for a small EVAP leak code.
Common causeParts:fuel cap - 6
Cracked or perished EVAP hoses/lines
Medium severityHeat-cycled vapor lines between tank, canister, and purge valve crack with age, producing a small steady leak.
Common cause
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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.