Evap leak fun...any Ford techs?

[01rangerxl]

So today I'm cruising down the road when the truck decides to throw the "check fuel cap" light at me. So I check fuel cap, and fuel cap is on.

I crawl under the truck to take a look. There are no visible leaks, but as I move closer to the vapor canister I catch a little bit of fuel smell.

The truck threw a P0457 code (no CEL though, only the check fuel cap light), which translates to "evap leak: fuel cap loose/off."

I went to Auto Zone and got a $10 CST fuel cap hoping I would get lucky and the light would go away, but that didn't help.

So how do I go about tracking this down? The code is no help. I figure it's either the canister itself or the purge valve, but those are expensive parts to play the guessing game with. Is there anything else it could be?

The truck runs fine BTW...nothing out of the ordinary except the light and faint smell around the vapor canister.

 

[jldcol]

Not a Ford or any other kind of tech, are the hoses to the evap can rigid or flex? are they damaged or loose? is the can properly attached? If the cel occured while driving it was perhaps caused by debris hitting/damaging something. I also think some or all of the evap cans are open to air and use a carbon type element to temporarily hold gas fumes, so the gas smell may be normal.

 

[01rangerxl]

The line is a solid plastic type material. There were no signs of damage. Everything was in place. The canister is protected by a shield and the spare tire.

 

[jldcol]

You may need more help than I can give. Sorry, and good luck.

 

[bdcardinal]

smoke test the system is the real way to test. the VMV is a common source for a leak besides the cap. i think yours is too new to have the dreaded $417 filler neck leak.

 

[punisher]

Originally Posted By: 01rangerxl

I crawl under the truck to take a look. There are no visible leaks, but as I move closer to the vapor canister I catch a little bit of fuel smell.


That is where you start. Look for loose/broken inlet/outlet or cracked cannister. That code denotes a big leak. Look first at any components susceptible to road FOD.

 

[mechtech2]

There should be a small vacuum line to the assembly under the hood, as well as the larger line.
First, take a close look and check the lines and EACH end.

There are electronics in the valve to control it. The connector or wiring may be bad, but this is not normal if someone did not play with them.
Try resetting the computer after your checks and see if the light comes back. Disconnect the battery for 5-10 minutes. Be ready to reset your clock and radio. It will run funny for a day or two, until it learns how to idle again.
It may be fixed already!

 

[punisher]

If the wiring is bad to the sensor or the purge flow valve you will get a dedicated code with the word "circuit" in the description.

 

[01rangerxl]

The vacuum line from the purge valve to the intake manifold was disconnected. I hope that's the root of all this. I'm going to erase the code and go for a drive.

 

[01rangerxl]

All is well now. I plugged the vacuum line in, erased the code, and all seems well. No more lights or smell.