P0446 on Nissan: How to Diagnose & Fix
Evaporative Emission Control System Vent Control Circuit
1 Nissan model · 1 documented issue · $100-$600 repair
P0446 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.
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
- 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)
P0446 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 P0446 mean on a Nissan?
P0446 stands for "Evaporative Emission Control System Vent Control Circuit." This emissions code points to a problem in the evaporative emission (EVAP) system's vent control circuit, which manages the vent valve that lets the charcoal canister breathe and seals it during leak tests. The EVAP system captures fuel vapors from the tank to keep them out of the atmosphere, and the vent valve must open and close on command for the system to work and self-test. The code sets when the engine computer detects an electrical or performance fault with this vent valve or its circuit. It usually causes only a check engine light with no driveability change, but it does prevent proper EVAP leak monitoring. On Nissan it is documented across 1 model: Frontier.
What are the most common causes of P0446?
The most common causes of P0446 are: Faulty EVAP vent control valve (solenoid), Wiring or connector fault in the vent valve circuit, Vent valve clogged with dirt, debris, or spider webs, Damaged or corroded vent valve connector, Blocked or pinched vent hose or filter, Faulty charcoal canister assembly, Faulty engine control module driver circuit. The specific cause varies by vehicle.
How much does it cost to fix P0446 on a Nissan?
Published repair estimates on Nissan range from $100 to $600 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.