P0455 on a 2019 Ford Edge

P0455 means the EVAP system failed a leak check badly enough that the computer sees a large leak or no pressure/vacuum change.

Not your vehicle? See general P0455 info.

Most common causes on the 2019 Ford Edge

Ranked from 736 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Purge valve/solenoid stuck fully open
High severity
The dominant, repeated pattern in this vehicle's complaints - purge valve replacements, a scan confirming the canister purge valve stuck open (code P0496), and a Purge Solenoid Valve failure that set an EVAP leak code (P0456) - is consistent with a valve stuck open providing a large, continuous leak path, matching a large-leak code.
Reported in 8 NHTSA complaints
Parts:purge valve
2
Fuel filler cap/neck not sealing during refueling
Medium severity
Reported fuel spillage from the filler gun points to a filler-neck or cap sealing problem large enough to register as a large leak.
Reported in 1 NHTSA complaint
Parts:fuel cap fuel filler neck
3
Missing or badly damaged fuel filler cap
Medium severity
A cap left off entirely or badly cracked is the classic large-leak cause on any EVAP-monitored vehicle.
Common cause
Parts:fuel cap
4
Disconnected or split EVAP hose/line
Medium severity
A hose popped off a fitting or split open creates a wide-open path to atmosphere.
Common cause
Parts:EVAP hose
5
Cracked charcoal canister housing
Low severity
A larger crack or split in the canister produces a leak big enough to fail the large-leak test.
Common cause
Parts:EVAP canister
6
Corroded or perforated fuel filler neck
Low severity
Advanced corrosion can open a leak path large enough to trigger the large-leak code.
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. P0455 on your car still needs shop confirmation before any repair.

Common symptoms

Check engine light
Fuel smell
Usually no performance issue
Failed emissions readiness

What to check before replacing parts

Check the gas cap first

Look for: A loose, missing, or cross-threaded cap is by far the most common cause of a large EVAP leak code — if it doesn't click to full tightness or the seal is cracked, that's very likely the whole fault.

Inspect visible EVAP hoses

Look for: A large leak is often obvious: a hose disconnected at a fitting, split open, or chewed through (rodent damage is common) rather than a hairline crack.

Command the purge and vent valves with a scan tool

Look for: A valve that doesn't respond at all when commanded open/closed, or stays open when it should seal, prevents the system from holding pressure/vacuum and reads as a large leak.

Smoke-test the system

Look for: With a large leak, expect an obvious plume of smoke or a clearly audible hiss at the fault location — it should be easy to spot compared to a small-leak diagnosis.

Inspect the canister and filler neck

Look for: A cracked charcoal canister housing or a corroded/rusted-through filler neck (common on older vehicles) can leak enough to prevent the system from ever holding vacuum.

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

Matching symptoms

Check Engine Light