P0455 on a 2019 Volkswagen Atlas

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 Volkswagen Atlas

Ranked from 466 NHTSA owner complaints filed for this vehicle.

Sort by:

1
EVAP purge valve (N80) / charcoal canister failure (large leak)
Medium severity
The same N80 purge valve and charcoal canister failures repeatedly diagnosed on this generation Atlas can present as a large leak when the valve sticks open, allowing continuous fresh-air flow through the EVAP system.
Reported in 9 NHTSA complaints
Parts:purge valve charcoal canister
2
Cracked EVAP hose or fuel tank/filler neck leak
Medium severity
Owners reported strong fuel smell and a recurring EVAP check-engine light traced to leaking fuel tank and lines requiring replacement, consistent with a large-leak fault.
Reported in 2 NHTSA complaints
Parts:fuel tank EVAP hose
3
Loose, missing, or unsealed gas cap
Low severity
A gas cap left loose or with a torn seal is the classic large-leak trigger; one owner specifically noted a bad vacuum seal at the filler.
Reported in 1 NHTSA complaint
Parts:fuel cap
4
Disconnected or split EVAP hose/quick-connect fitting
Medium severity
A hose that pops off the canister or purge line creates an open path to atmosphere large enough to fail the large-leak monitor.
Common cause
Parts:EVAP hose
5
Cracked charcoal canister housing
Low severity
Age or heat-cycling can crack the plastic canister body itself, producing a leak too large for the system to compensate for.
Common cause
Parts:charcoal canister
6
Rusted or damaged fuel filler neck
Low severity
Corrosion perforating the filler neck creates a large, constant leak path that the small-leak test would never see intermittently.
Common cause
Parts:fuel filler neck

Part links go to Amazon search results for this vehicle. As an Amazon Associate, WrenchConnect earns from qualifying purchases — always confirm fitment for your exact trim and engine before ordering.

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