P0456 on Infiniti: How to Diagnose & Fix
Evaporative Emission Control System Leak Detected (Very Small Leak)
1 Infiniti model · 1 documented issue · $40-$450 repair
P0456 on Infiniti by model: symptoms, diagnosis and fix
Owners occasionally report check-engine lights caused by EVAP system leaks, often related to the gas cap, purge control valve, vent valve, or associated hoses. These faults usually do not affect drivability much, but they can prevent emissions readiness and trigger recurring warning lights.
Common Symptoms
- Check engine light on
- Loose or worn gas cap
- Failed emissions inspection
- Occasional fuel vapor smell
- No major drivability change
How to Fix
Diagnosis starts with reading EVAP-related codes, inspecting the fuel cap seal, and smoke-testing the EVAP system for leaks. Repairs may be as simple as replacing the gas cap or may require a purge/vent solenoid and hose replacement; typical cost runs from about $40 to $450 depending on the fault.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti early-production fuel filler capOEMInfiniti 17251-1NC0B
The 2010-2011 overlap with 4BA0B reflects production/supersession changes; confirm VIN and cap/filler-neck configuration rather than choosing
- Genuine Infiniti current-production fuel filler capOEMInfiniti 17251-4BA0B
Confirm VIN/build because 2010-2011 overlaps the earlier 1NC0B branch.
- Genuine Infiniti VK50VE EVAP purge-control valveOEMInfiniti 14930-JA10D
It is not the canister vent valve; confirm VIN and connector.
- Genuine Infiniti EVAP canister vent-control valveOEMInfiniti 14935-JF02C
vent-valve branch after P0447 circuit and smoke/command testing proves the valve failed Fitment/availability: Infiniti 14935-JF02C supersedes the JF00A-E family and is cataloged for the 2009-2013 FX50 EVAP vent position. Test wiring and …
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Owner tips & cautions
- TipDo a smoke test before replacing multiple EVAP parts; small hose leaks are easy to miss visually.
- TipClear the code only after tightening or replacing the cap and completing a few drive cycles.
P0456 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0456 mean on a Infiniti?
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 Infiniti it is documented across 1 model: FX50.
What are the most common causes of P0456?
The most common causes of P0456 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P0456 on a Infiniti?
Published repair estimates on Infiniti range from $40 to $450 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0456 on a different make?
View P0456 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.