EmissionsSeverity Low: usually safe to drive

P0455Evaporative Emission System Leak Detected (Large Leak)

What it means

The EVAP leak test found a large leak or no flow at all: the system can't build vacuum.

Symptoms

Check engine light
Possibly a fuel smell
Usually no change in how the car drives

Common causes

Fuel cap missing or not tightened
Disconnected or split EVAP hose
Purge valve stuck closed
Cracked canister

What to check first

Check the fuel cap first
Smoke-test the system
Check the purge valve opens on command

Can I drive with P0455? Usually yes. P0455 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0455: questions and answers

What does P0455 mean?

P0455: Evaporative Emission System Leak Detected (Large Leak). The EVAP leak test found a large leak or no flow at all: the system can't build vacuum.

What are the symptoms of P0455?

Check engine light. Possibly a fuel smell. Usually no change in how the car drives.

What causes P0455?

Fuel cap missing or not tightened. Disconnected or split EVAP hose. Purge valve stuck closed. Cracked canister.

How do you diagnose P0455?

1. Check the fuel cap first 2. Smoke-test the system 3. Check the purge valve opens on command

Can I drive with P0455?

Usually yes. P0455 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.