Hyundai Check Engine Code
P0455 on Hyundai
Evaporative Emission Control System Leak Detected (Large Leak)
Also covers: Kia, Genesis
P0455 on Hyundai: what makes it different
P0455 (large EVAP system leak) is one of the most frequent codes on Hyundai vehicles. The EVAP system on Hyundais is sensitive to gas cap sealing and purge/vent valve condition, and the canister assembly is often mounted where it's exposed to road debris.
Most-affected engines
- Theta II 2.4L (Sonata, Santa Fe, Tucson)
- Gamma 1.6L/1.8L (Elantra, Accent)
- Nu 2.0L (Elantra, Tucson)
- Lambda 3.3L/3.8L V6 (Sonata, Santa Fe, Genesis)
Common model years: 2006–2020
Most likely cause on Hyundai
Loose, cross-threaded, or worn-out gas cap seal — the cheapest and most common fix on Hyundai EVAP P0455 codes.
Known Hyundai engine-family issues
Hyundai purge control solenoids (PCSV) mounted on or near the intake manifold are a known wear item and often the culprit when a new gas cap doesn't clear the code. The rear-mounted canister and CCV on SUVs like the Santa Fe and Tucson are exposed and prone to corrosion or debris damage.
Hyundai-specific causes (most common first)
- Gas cap not tightened to clicks or worn rubber seal
- Failed EVAP purge control valve (PCSV) stuck open
- Cracked or disconnected EVAP hose near the canister
- Failed canister close valve (CCV) at rear of vehicle
- Damaged charcoal canister from road debris/water intrusion
- Leaking fuel filler neck or check valve
Hyundai-specific diagnostic tip
Start with the gas cap — remove it, inspect the rubber seal for cracking or dryness, then reinstall until it clicks at least 3 times. If the code returns, use a smoke machine introduced at the service port; on Hyundais, smoke usually shows at the purge valve or where the rear canister hoses meet the CCV.
Symptoms drivers report
- Check engine light
- Fuel smell around the car (occasional)
Typical repair cost on Hyundai
Most Hyundai owners fix P0455 for between $20 and $400, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Loose, cross-threaded, or worn-out gas cap seal — the cheapest and most common fix on Hyundai EVAP P0455 codes. — before throwing parts at it.
Hyundai P0455 FAQ
Can I still drive my Hyundai with a P0455?
Yes, P0455 doesn't affect drivability — it only indicates a fuel vapor leak. However, you'll fail emissions testing, and you may notice a fuel smell. Address it within a few weeks.
I replaced the gas cap on my Hyundai Sonata and P0455 came back. Now what?
Next most likely culprit is the purge control solenoid valve (PCSV) on the intake manifold. It commonly sticks open on Theta II engines. After that, inspect the rear charcoal canister and canister close valve for damage.
Related codes
Drive a different make? See the general P0455 guide for cross-vehicle causes and symptoms.
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Most common fix for P0455:
Replacement gas capAs an Amazon Associate, AXLY earns from qualifying purchases. General P0455 guide →