P0456 on Toyota
Evaporative Emission Control System Leak Detected (Very Small Leak)
P0456 on Toyota vehicles indicates evaporative emission control system leak detected (very small leak). Au7o has documented this code across 2 Toyota models — most commonly on FJ Cruiser, Tacoma. This emissions code means the evaporative emission (EVAP) control system has detected a very small leak — even tinier than the one flagged by P0442, roughly equivalent to a 0.020-inch hole. The EVAP system traps fuel vapors from the tank and prevents them from escaping into the atmosphere, and the computer tests for leaks by sealing the system and watching for pressure or vacuum loss. Because the leak is so small, the cause is often subtle, but a loose or worn gas cap is still the most common and easiest to check. It generally indicates a minor seal, hose, or valve leak somewhere in the fuel vapor system. Typical repair costs on Toyota range from $20 to $2,500, depending on the specific model and root cause.
Common Causes of P0456
- •Loose, worn, or faulty gas cap or cap seal
- •Cracked or loose EVAP hose or line
- •Leaking vent valve or purge valve not sealing
- •Damaged O-ring or seal at the fuel filler neck
- •Small crack or leak in the charcoal canister
- •Leaking fuel tank or sending unit gasket
- •Loose or corroded EVAP component connection
P0456 on Toyota by Model
Toyota FJ Cruiser(1 issue)
- A/C Compressor and Evaporator Failure2007-2014
The FJ Cruiser's A/C system is prone to compressor clutch failure and evaporator core leaks. The evaporator is located behind the dashboard, making replacement extremely labor-intensive. The A/C system struggles in hot climates, especially when off-roading at low speeds.
Toyota Tacoma(1 issue)
- A/C Musty/Mold Smell2016-2023
The A/C system can develop a musty or moldy smell when first turned on. This is caused by moisture accumulation and mold/bacteria growth on the evaporator. Common in humid climates and vehicles that use A/C infrequently.
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View P0456 across all makes →Frequently Asked Questions
What does P0456 mean on Toyota?▼
P0456 stands for "Evaporative Emission Control System Leak Detected (Very Small Leak)." This emissions code means the evaporative emission (EVAP) control system has detected a very small leak — even tinier than the one flagged by P0442, roughly equivalent to a 0.020-inch hole. The EVAP system traps fuel vapors from the tank and prevents them from escaping into the atmosphere, and the computer tests for leaks by sealing the system and watching for pressure or vacuum loss. Because the leak is so small, the cause is often subtle, but a loose or worn gas cap is still the most common and easiest to check. It generally indicates a minor seal, hose, or valve leak somewhere in the fuel vapor system. On Toyota specifically, this code is documented across 2 models.
What causes P0456 on Toyota vehicles?▼
Common causes on Toyota: Loose, worn, or faulty gas cap or cap seal, Cracked or loose EVAP hose or line, Leaking vent valve or purge valve not sealing, Damaged O-ring or seal at the fuel filler neck, Small crack or leak in the charcoal canister. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0456 on a Toyota?▼
Repair costs on Toyota range from $20 to $2,500, depending on the specific model and root cause.
Which Toyota models have P0456 documented?▼
Au7o has documented P0456 on 2 Toyota models: FJ Cruiser, Tacoma.