Quick Solving P0446 Ford F150 Error Code

Is P0446 serious? It is not so severe as it does not cause any immediate danger. You can still run your car with this code and check the engine light. You may face some issues with your vehicle and see some symptoms like reduced fuel economy for this error code but running the vehicle is okay.

This P0446 Ford F150 error code is associated with the EVAP system. The job of this system is to receive fuel vapor and sends it to the engine so that the machine can ignite the combustion process. The error code appears if this EVAP control system vent circuit slows or no longer responds.

So, it is essential to solve issues as it will make you run to the gas station frequently. So, learn the causes, symptoms, and solutions to this error code in detail.

Causes and Symptoms of P0446 Ford F150 Code

Let’s find out all the causes behind this code appear.

Defective vapor canister purge valveReduced gas mileageCheck engine light
Faulty EVAP systemEngine stallsEngine misfires
Defective charcoal canisterThe engine makes a hissing noiseFuel odor appear
Faulty fuel tank sending unitWrong data transmission about fuel status
Faulty fuel capFuel odorLow fuel economy
Faulty fuel filler neckFuel leaksFuel smells

There are a few reasons behind the P0446 Ford F150 code appearing and some simple solutions. Know them and have a risk-free ride.

Faulty Vapor Canister Purge Valve

When the vapor canister purge valve is faulty, the check engine light will first be on, and the P0446 code 2010 Ford f150 seems to appear. Then it will adversely affect the gas mileage as the valve will not open properly. If this problem continues in the long term, the engine will be affected soon.

Solution: The only solution to the defective vapor canister purge valve is to replace it. It is a relatively easy process to replace the purge valve.

EVAP System Hose Faulty

The EVAP system Hose carries the fuel vapor from the tank to the engine intake manifold. It can be faulty and leak.

Again, the P0446 Ford f150 3.5 engine can appear due for some reason. When running your truck, the engine will start to stall or surge. The engine may misfire when the problem is running the car for the long term. You will see a lack of power in the machine.

Solution: Check the hose if there is any tear or hole. Replacing the hose is the wise step instead of repairing it.

Defect in Charcoal Canister

When the charcoal canister is faulty, it will cause issues with fuel tank filling steps, and it seem to appear as P0446 Ford f150 3.5 EcoBoost.

On opening the fuel tank cap, it will create a hissing noise. You will get exhausted smoke and fuel odor which is unpleasant.

Solution: When the charcoal canister is faulty, it fails the emission test. It is impossible to repair the charcoal canister in the truck, so you have to replace it.

Faulty Fuel Tank Sending Unit

The fuel gauge sending unit record the fuel level and send the data to the fuel gauge. If it is faulty, it cannot transmit the data correctly. The symptom of a lousy fuel tank sending unit is erratic behavior. It will show empty fuel status or over-full fuel status.

When you find the fuel gauge acting like this and the P0446 Ford F150 5.0 issue, you can ensure that the fault is in the fuel tank sending unit.

Solution: If the fuel tank sending unit is found faulty, you have to reset it or the system.

Faulty Fuel Cap

When the fuel cap is faulty, it will message that the cap is off. On inspection, you may find that the cap is actually ON. You may need to tighten the fuel cap. Frequent fuel cap tightening turns into a bad fuel cap. The system will show the P0446 Ford F150 5.4 code as most users with this engine are complaining. You will also get a bad fuel smell from the engine. The fuel economy will also be poor.

Solution: Instead of repairing or frequent tightening, it is wise to replace the fuel cap as soon as possible. So, when you find a problem with the fuel cap, consider replacing it.

Faulty Fuel Filler Neck

The fuel filler neck is lined to the gas tank through a gasket. If the gasket gets dried out, the fuel tank cannot hold the fuel pressure longer. It happens when the truck is running through the dry climate for a long time.

When this filler neck is wrong, it starts to leak, and the fuel smell gets out. The check engine light appears, and the P0446 Ford F150 5.4 may show. 

This problem is severe as it leaks fuel and can cause fire hazards. So, immediate checking is required.

Solution: There is no shortcut or repairing for a bad fuel filler neck. You have to replace the filler neck immediately after getting the code.

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Frequently Asked Questions (FAQs)

How do I fix code p0446?

When your truck system shows the P0446 error code, you must look for specific symptoms. According to the symptoms, check the necessary items which cause this code to appear. The essential parts for this code are the canister purge valve, fuel tank sending unit, fuel cap, charcoal canister, fuel filler neck, EVAP hose, etc. If any parts are faulty, replace them.

What does the P0446 code mean?

The P0446 code means some issues with the EVAP system control circuit. When there is improper electrical resistance, the EVAP control circuit has a voltage drop. It causes the EVAP vent valve to malfunction.

Can I drive with a P0446 code?

Yes, you can continue driving even if there is a P0446 error code from the system. It is because this code does not put you in immediate trouble. But you will start to face a problem with low fuel economy, reduced gas mileage, and low power in the engine. So, if it is possible, you should solve the issue soon.


Though the P0446 Ford F150 error code does not show any immediate issue, you may drive the vehicle or keep running it in the middle of the journey. But the wisest decision is to solve the matter as soon as possible. The long-term problem with the EVAP control circuit may cause severe issues. Some problem creates engine misfires. It can ultimately damage the engine. Since some reasons behind this code can be severe, you should be careful and take this point seriously.

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D Conroy

Meet our senior writer and content manager of Automasterx. He has worked in several mechanical garages and mastered different vehicle diagnoses and parts repair. He never stops until finding out the ultimate solutions for any vehicle fault code. However, ensuring the only solid solutions for each vehicle malfunction is his core part of the duty, alongside analyzing fault codes and signals.

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