How much does it cost to fix P0455 on a Chevy?

Repair costs for P0455 on Chevy vehicles typically range from $20 to $350 depending on the underlying cause. The most common fix is: Loose, damaged, or missing gas cap seal.

Chevy Check Engine Code

P0455 on Chevy

Evaporative Emission Control System Leak Detected (Large Leak)

Severity: low DIY difficulty: 1/5 Chevy cost: $20–$350

Last updated April 30, 2026 Also covers: Chevrolet, GMC, Buick, Cadillac, GM

P0455 on Chevy: what makes it different

On Chevy gasoline vehicles, P0455 means the EVAP system has detected a large leak — enough that fuel vapor can escape rather than being properly captured and burned. This is one of the most common EVAP codes across Chevy cars, crossovers, and trucks because the system relies on several rubber and plastic components exposed to weather and road conditions.

Most-affected engines

Applies broadly across Chevy gasoline engines with EVAP systems
Commonly reported on Silverado/Equinox/Malibu/Cruze platforms

Common model years: 2007–2018

Most likely cause on Chevy

Loose, damaged, or missing gas cap seal

Known Chevy engine-family issues

Several GM compact SUV and sedan platforms route the EVAP canister vent valve low near the fuel tank, which increases exposure to road salt and moisture over time and can lead to the valve sticking or corroding.

Chevy-specific causes (most common first)

Gas cap not tightened fully or worn/cracked seal
Faulty EVAP canister vent valve sticking open (common on compact SUVs/sedans)
Cracked or deteriorated rubber fuel filler neck hose from age and UV exposure
Damaged EVAP lines near the undercarriage from road debris (more common on trucks)
Faulty fuel tank pressure sensor producing a false large-leak reading

Chevy-specific diagnostic tip

Start with the cheapest and most common fix: remove, inspect, and reseat or replace the gas cap, then clear the code and let the EVAP monitor run through a few complete drive cycles before assuming a bigger leak is present.

Symptoms drivers report

Check engine light
Fuel smell around the car (occasional)

Typical repair cost on Chevy

Most Chevy owners fix P0455 for between $20 and $350, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Loose, damaged, or missing gas cap seal — before throwing parts at it.

Chevy P0455 FAQ

Will a loose gas cap really trigger a check engine light on my Chevy?

Yes — a loose or worn gas cap is the single most common cause of P0455 on Chevy vehicles because it immediately creates a path for vapor to escape the sealed system.

How long after fixing the issue will my Chevy's check engine light turn off?

The EVAP monitor usually needs several complete drive cycles with the fuel level in a certain range to confirm the leak is gone and clear the code on its own.

Can cold weather make P0455 appear on my Chevy?

Cold weather can cause rubber hoses and seals to contract and reveal small cracks, which is why this code is often reported more frequently in winter months.