HELP WITH CODE P0456

[HAMMER]

MY CHECK ENGINE LIGHT CAME ON THE OTHER DAY, SO I HOOKED UP MY SCANNER AND IT READ P0456 EVAPORATIVE EMISSION SYSTEM LEAK DETECTED. I CLEARED THE CODE AND MY CHECK ENGINE LIGHT WENT AWAY, BUT THE CODE STILL SHOWS AS PERMANENT. HAS ANYONE HAD ANY EXPERIENCE WITH THIS ONE? WHAT WAS THE FIX AND HOW TO CLEAR THE PERMANENT CODE. I WOULD RATHER FIX IT MYSELF VS. TAKING TO THE DEALER AND IT BE THERE FOR A WEEK OR MORE. ANY HELP WOULD BE APPRECIATED. THANKS.

 

[l1tech]

Is everything stock? One of the 1st things I do on Ford's with the capless fuel filler neck is to take the funnel that is supplied to put gas in the car in case of emergency and install and remove it a few times in the filler neck. Clear the codes and see if they come back. The permanent code will disappear only after the test that caused the code in the 1st place runs and passes. If that doesn't fix it for you you may want to consider taking it in because small evap leaks can be extremely hard to locate and throwing parts at a problem can get expensive.

 

[tfran1521]

MY CHECK ENGINE LIGHT CAME ON THE OTHER DAY, SO I HOOKED UP MY SCANNER AND IT READ P0456 EVAPORATIVE EMISSION SYSTEM LEAK DETECTED. I CLEARED THE CODE AND MY CHECK ENGINE LIGHT WENT AWAY, BUT THE CODE STILL SHOWS AS PERMANENT. HAS ANYONE HAD ANY EXPERIENCE WITH THIS ONE? WHAT WAS THE FIX AND HOW TO CLEAR THE PERMANENT CODE. I WOULD RATHER FIX IT MYSELF VS. TAKING TO THE DEALER AND IT BE THERE FOR A WEEK OR MORE. ANY HELP WOULD BE APPRECIATED. THANKS. View attachment 16463

Purge valve needs to be replaced.
I just had this done a few months ago.
The dealership didn't keep the car, they just verified what needed to be replaced then ordered the part. I drove the car until the part came in
With this code the car would take longer to start the immediately after filling it up with gas. Then would be normal until I filled up again

 

[hbalek]

Purge valve needs to be replaced.
I just had this done a few months ago.
The dealership didn't keep the car, they just verified what needed to be replaced then ordered the part. I drove the car until the part came in
With this code the car would take longer to start the immediately after filling it up with gas. Then would be normal until I filled up again

I learned from my last vehicle, 2013 MKZ, overfilling at the gas pump causes this. Mine never had the check engine light but after some fill ups the engine would seem to stall at idle and would go back to normal after a short drive.

 

[tfran1521]

I learned from my last vehicle, 2013 MKZ, overfilling at the gas pump causes this. Mine never had the check engine light but after some fill ups the engine would seem to stall at idle and would go back to normal after a short drive.

i can promise you that ive never filled it up past the shut off.
it was probably just luck of the draw.
i did have the recall done for the fuel filler hose or whatever it was but when the pump stops i dont try to get extra.. and im the only one that fill up any of our cars

 

[HAMMER]

The only modification I've done so far is a thermal exhaust. Plan on putting on a whipped intercooler in a few days. No tune as of now. Ill just go ahead and make a appointment to drop it off at the dealer and let them take care of it.

 

[HAMMER]

Is everything stock? One of the 1st things I do on Ford's with the capless fuel filler neck is to take the funnel that is supplied to put gas in the car in case of emergency and install and remove it a few times in the filler neck. Clear the codes and see if they come back. The permanent code will disappear only after the test that caused the code in the 1st place runs and passes. If that doesn't fix it for you you may want to consider taking it in because small evap leaks can be extremely hard to locate and throwing parts at a problem can get expensive.

Everything stock except thermal exhaust. How often are these test performed?

 

[l1tech]

Evap tests are usually run within the 1st 30 minutes that a vehicle has been started after it has sat overnight adn certain driving conditions have been met however you can get it to run even if it has not sat overnight by clearing the codes and then starting the engine without turning the ignition off immediately after clearing the codes but the driving conditions still have to be met. The evap system will also run a quick gross leak test immediately after gas has been added to the fuel tank.

 

[HAMMER]

So I took in to ford, and of course they could not find anything wrong with it. They did not change anything. I installed a whipped intercooler, test drive went good and then the check engine light came back on . Hooked up scanner and the same p0456th code came on. I can either take it back in a, or fix it myself

 

[FORZDA3]

Your dealer service tech is a lazy ****. The problem is most likely the fuel filler neck valve leaking. Their Ford diag tool can run the leak test to determine the fault and help isolate the root cause.
Whenever the CE light comes on, do NOT reset the code and take it back to the (a different) dealer.

 

[HAMMER]

Supposedly they ran all the leak tests with their diagnostic tool. This was shown to have been done according to the paperwork that I received when I picked it up.

 

[Cajun Heat]

Supposedly they ran all the leak tests with their diagnostic tool. This was shown to have been done according to the paperwork that I received when I picked it up.

As @FORZDA3 mentioned, don't clear the code and take it to a dealer. I have had good experiences with AutoNation Ford in Katy.

 

[HAMMER]

Will do, thanks

 

[Badgerfan79]

Will do, thanks

What did you find out?

 

[HAMMER]

dealer found a leak on the fuel filler tube/hose near the gas tank. They replaced the hose and all seals.

 

[Badgerfan79]

dealer found a leak on the fuel filler tube/hose near the gas tank. They replaced the hose and all seals.

Nice. Don't suppose that is covered by power train warranty....I just got the p0456 code but I hit 37K so the bumper to bumper is expired.