P0440 on Nissan: How to Diagnose & Fix
Evaporative Emission Control System Malfunction
2 Nissan models · 2 documented issues · $100-$700 repair
P0440 on Nissan by model: symptoms, diagnosis and fix
The evaporative emissions system on these trucks commonly develops faults from a sticking vent control valve, saturated charcoal canister, cracked hoses, or rust/dirt intrusion near the rear-mounted canister. Nissan published EVAP-related service bulletins for leak and vent valve diagnosis on Frontier/Xterra-era trucks.
Common Symptoms
- check engine light
- intermittent EVAP leak code
How to Fix
Diagnosis should include smoke testing the EVAP system, checking the vent control valve operation, inspecting canister hoses and purge lines, and verifying the gas cap seals properly. Repairs range from replacing the vent valve or damaged hoses to replacing the charcoal canister assembly if fuel saturation or contamination is present, then clearing codes and completing a drive cycle.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Nissan EVAP purge control valve 14930-5M00A
2000-2004 Frontier 2.4L and 3.3L applications on the live fitment table; confirm VIN and current supersession.
- Genuine Nissan EVAP pressure/drain-cut valve 14935-5M00B
Confirm VIN.
- Genuine Nissan EVAP canister 14950-5S601
Confirm VIN.
- Standard Motor Products CP3090 carbon canister
Direct listing covers 2001-2003 Frontier 2.4L and 2004 through 07/01/2004; verify the exact production date and live application before purchase.
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Owner tips & cautions
- TipBefore replacing the canister, test the gas cap and vent valve first; many owners solve the code with the valve or cracked hose rather than the full canister.
Sources for this issue (3)
In rust-belt climates, the Sentra's steel fuel filler neck commonly corrodes where road salt and debris collect behind the left rear wheel area. Owners report a strong gasoline odor after fill-ups, visible rust holes, EVAP leak codes, and in some cases fuel dripping during refueling. There is no Nissan recall for filler neck corrosion on this Sentra; the only related Sentra recall (05V269, 2005 models) covers an incorrectly formed vapor hose inside the fuel tank.
Common Symptoms
- gasoline smell near left rear of vehicle
- fuel leak while filling tank
- check engine light with EVAP leak code
- visible rust on filler neck
- difficulty passing emissions inspection
How to Fix
Inspect the filler neck and vent tube for scaling, pinholes, and wet fuel residue, especially near the wheelhouse and hose connections. Replace the filler neck assembly and any degraded hoses or clamps, then clear EVAP codes and confirm the system passes a smoke test. In severe rust areas, inspect surrounding body metal and shield liners as well.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Nissan B15 filler tube assembly 17221-5M001
Confirm VIN, production date, engine/emissions configuration and all connected hose diameters; not the 2005-2006 ZG50A branch.
- FNN030 replacement fuel filler neck for 2006 Sentra
Confirm VIN/emissions/build and hose routing.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipUse new clamps and vent hoses when replacing the neck, because old hoses often crack when disturbed.
P0440 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 P0440 mean on a Nissan?
P0440 stands for "Evaporative Emission Control System Malfunction." This code indicates a general malfunction in the Evaporative Emission Control (EVAP) system, which captures fuel vapors from the gas tank and routes them to be burned by the engine instead of escaping into the air. The computer ran a self-test and detected the sealed vapor system isn't holding pressure or vacuum correctly, often signaling a leak somewhere in the system. The most frequent and easiest cause is a loose or faulty gas cap. The car will run normally, but it will fail an emissions test and may smell faintly of fuel. On Nissan it is documented across 2 models: Frontier, Sentra.
What are the most common causes of P0440?
The most common causes of P0440 are: Loose, damaged, or missing gas cap, Cracked or disconnected EVAP hose, Faulty purge valve/solenoid, Faulty vent valve/solenoid, Leaking charcoal canister, Damaged fuel tank filler neck or seal, Faulty leak detection pump or pressure sensor. The specific cause varies by vehicle.
How much does it cost to fix P0440 on a Nissan?
Published repair estimates on Nissan range from $100 to $700 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.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.