Is it safe to drive with a P0455 code?

Severity is low. Address P0455 sooner rather than later — driving with an active check engine light can worsen the problem or void emissions warranties.

How much does it cost to fix P0455?

Repair costs for P0455 typically range from $0 to $400 in the US, depending on the underlying cause. The most common fix is: Gas cap completely off or loose.

What are the symptoms of P0455?

Check engine light. Fuel smell around the car (occasional).

Check Engine Code

P0455

Evaporative Emission Control System Leak Detected (Large Leak)

Severity: low DIY difficulty: 1/5 Typical cost: $0–$400

Last updated April 30, 2026

What P0455 means

Large-leak version of P0442. Often set immediately after refueling if the gas cap was left loose or not turned until it clicks.

Vehicle-specific P0455 guides

P0455 can mean different things on different vehicles. Pick your make for engine-family specifics:

P0455 on Hyundai → P0455 on Toyota →

Symptoms

Check engine light
Fuel smell around the car (occasional)

Likely causes (most common first)

Gas cap completely off or loose
Large hose disconnected or cracked
Failed purge valve stuck open
Big crack in the filler neck

Can I keep driving?

Low — mostly emissions/economy

Typical repair cost

DIY fixes can start near $0 (parts only). Shop repairs for P0455 typically run up to $400 depending on the underlying cause and vehicle. Start with the most common cause — Gas cap completely off or loose — before throwing parts at it.