P0455 Code: Evaporative Emission Control System Leak Detected (Large Leak)

🟢 Low severity · drivable

Safe to drive — this is an emissions leak, not an engine problem. Fix it before your next emissions test.

What P0455 means

The evaporative emission (EVAP) system has a large leak, meaning fuel vapors are escaping. It's usually something simple like a loose gas cap or a disconnected hose.

Symptoms

Check engine light is on
Possible fuel smell
Usually no driving symptoms

Common causes

most common: Loose, missing, or damaged gas cap
common: Disconnected or cracked EVAP hose
common: Faulty EVAP purge or vent valve
less common: Crack in the charcoal canister or filler neck

How to fix it

Fix	DIY?	Typical cost
Tighten or replace the gas cap	Yes	$10–30
Inspect and reconnect or replace cracked EVAP hoses	Yes	$10–60
Have a smoke test performed to find the exact leak	Mechanic	$50–150
Replace a faulty purge or vent valve	Yes	$30–120

Frequently asked questions

Can I drive with a P0455 code?

Yes. It's an emissions leak and doesn't affect how the car runs. Fix it before your next emissions test.

What is the most common cause of P0455?

A loose or missing gas cap. Always check the cap first — it's the cheapest and most common fix.

Is P0455 expensive to fix?

Usually not. Most fixes are under $150. It only adds up if the charcoal canister or fuel tank itself is cracked.

Related codes

P0456 Code: Evaporative Emission System Leak Detected (Very Small Leak)

P0442 Code: Evaporative Emission Control System Leak Detected (Small Leak)

P0440 Code: Evaporative Emission Control System Malfunction

P0455 by vehicle brand

Causes and repair costs for P0455 differ between makes. Pick your brand for the specifics.

P0455 on a Toyota

P0455 on a Honda

P0455 on a Ford

P0455 on a Chevy

P0455 on a Nissan

P0455 on a Mercedes-Benz

P0455 on a Volkswagen

P0455 on a Hyundai

P0455 on a Subaru

P0455 on a Mazda

P0455 on a Jeep

P0455 on a Lexus

P0455 on a Volvo

Related guide: How to Reset a Check Engine Light →

Updated 2026-08. This page is informational and not a substitute for professional diagnosis.