P0455 on a 2017 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 2017 Ford Edge

Ranked from 1,300 NHTSA owner complaints filed for this vehicle.

Sort by:

1
EVAP purge valve/solenoid failure
High severity
Multiple owners of this exact vehicle report a failed EVAP canister purge valve/solenoid throwing code P1450, causing stalling and hard starts after refueling.
Reported in 5 NHTSA complaints
Parts:EVAP purge valve purge valve solenoid
2
Fuel filler neck housing leak
Medium severity
One owner's EVAP control system fault was traced to a leaking fuel filler neck housing.
Reported in 1 NHTSA complaint
Parts:fuel filler neck
3
Loose, damaged, or missing gas cap
High severity
By far the most common cause of a large-leak EVAP code.
Common cause
Parts:gas cap
4
Cracked or split EVAP vapor line/hose
Medium severity
A larger split or disconnected line produces the large-leak threshold.
Common cause
Parts:EVAP hose
5
EVAP vent valve stuck open
Medium severity
A vent valve that won't seal produces an immediate large-leak result on the self-test.
Common cause
Parts:EVAP vent valve
6
Charcoal canister crack
Low severity
A cracked or split canister housing is a common large-leak source.
Common cause
Parts:charcoal canister

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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