P0442 on a 2016 Mazda Cx 5

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 Mazda Cx 5

Ranked from 507 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Damaged or melted fuel filler neck/pipe
High severity
One owner's filler pipe melted, causing a fire — a compromised filler neck is a direct EVAP leak path even at smaller leak severity.
Reported in 1 NHTSA complaint
Parts:fuel filler neck
2
Fuel system component defect covered by an NHTSA recall campaign
Medium severity
An owner cites active NHTSA recall campaign 16V064000 for the fuel system on this vehicle, consistent with a manufacturer-acknowledged vapor/fuel system integrity issue.
Reported in 1 NHTSA complaint
3
Noticeable fuel odor consistent with a small vapor leak
Low severity
An owner reports smelling gas around the car on cold starts, a classic symptom of a small EVAP system leak.
Reported in 1 NHTSA complaint
4
Loose, worn, or improperly seated gas cap
Low severity
The single most common small-EVAP-leak cause on any vehicle.
Common cause
Parts:fuel cap
5
Cracked purge valve
Low severity
A purge valve that doesn't seal fully at idle produces a small, steady leak the EVAP monitor detects.
Common cause
Parts:purge valve
6
Charcoal canister crack
Low severity
A hairline crack in the canister housing is a common age-related small-leak source.
Common cause
Parts:charcoal canister
7
Cracked or brittle EVAP hose
Low severity
Age and heat-cycling crack the rubber/plastic EVAP lines, a standard small-leak cause.
Common cause
Parts:EVAP hose

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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