P0455 on a 2019 Ford Ecosport

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 Ecosport

Ranked from 451 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Purge valve failure/stuck open
Medium severity
Owner reports repeated no-start/stalling on refueling; Ford service replaced the purge valve, consistent with an EVAP purge-side fault.
Reported in 1 NHTSA complaint
Parts:purge valve
2
EVAP hardware disturbed during repeat engine-replacement service
Low severity
Owner reports EVAP components were replaced alongside two engine swaps performed under the 23S64 oil-pump recall, raising the chance of a mis-seated line or connector from the repeat teardown.
Reported in 1 NHTSA complaint
3
Loose, damaged, or missing gas cap
Low severity
Check for a cracked seal or cap that doesn't click into place; the most common trigger for a large-leak EVAP code.
Common cause
Parts:gas cap
4
Cracked or perished EVAP hose/line
Medium severity
Inspect the rubber/plastic lines between canister, purge valve, and tank for cracking or chafing.
Common cause
5
EVAP vent valve failure (stuck open)
Medium severity
A vent valve that won't seal lets the system leak down; smoke-test to confirm.
Common cause
Parts:EVAP vent valve
6
Charcoal canister crack or saturation
Low severity
A cracked or fuel-soaked canister will not hold vacuum during the EVAP monitor.
Common cause
Parts:charcoal canister
7
Rusted or deformed fuel filler neck
Medium severity
Common on higher-mileage or rust-belt vehicles; check for perforation near the cap seat.
Common cause

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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