Code P04F0 issue

[EdgeWis713]

I've had a Code: P04F0 - EVAP System High Load Purge Line 'A' Performance for a while now, on and off since January 2026.

 

I have a vLinker FS in the OBD port at all times and use FORScan Lite on my phone. This is on a 2022 Edge SEL.

 

Initially, I traced it to a faulty purge valve, so I replaced it with the whole hose & purge valve assembly mid-February and the check engine light went away, for a whole 2 months (approximately).

 

Mid-April the check engine light came back, same code, so I bought just the Purge Valve and replaced it, even though it didn't seem like the old (new) one was bad, then cleared the code and everything was fine, for a couple of weeks anyway, then the check engine light was back. A bunch of research later and I went to the next possible part and replaced the Vapor Canister Vent Solenoid in May. Unfortunately, that still didn't fix anything so I broke down and bought a smoke machine. I ran a test through the gas cap and found the smoke leaking from only one place, the top drivers side of the gas tank.

 

I have not dropped the tank yet as I don't have a lift and I'm not sure how to go about it in my driveway. The question is, could this possibly be something simple like the seal on the drivers side fuel pump is bad or could it be something more nefarious?

 

I've also noticed that the code doesn't show up when the gas tank is between 3/4 - full, only once it's below 3/4 does the code appear and pretty much every time I start the car.

 

Any ideas? I'm getting pretty tired of having to clear code anytime I get in the car.

 

Thanks,

-Trevor

Edited August 20 by EdgeWis713

[1004ron]

Welcome.

 

On the purge valve - I've followed a similar path, replaced the complete assembly with a 3rd party brand, replaced just the solenoid and both had a very short life - I'm on an OEM one for about 7 months with no issues.

[Samurai Edge]

On 8/20/2026 at 2:49 PM, EdgeWis713 said:

I've had a Code: P04F0 - EVAP System High Load Purge Line 'A' Performance for a while now, on and off since January 2026.

 

I I ran a test through the gas cap and found the smoke leaking from only one place, the top drivers side of the gas tank.

 

I have not dropped the tank yet as I don't have a lift and I'm not sure how to go about it in my driveway. The question is, could this possibly be something simple like the seal on the drivers side fuel pump is bad or could it be something more nefarious?

 

Thanks,

-Trevor

 

I would think there should not be any leaking at all from the gas tank, but that's me as it doesn't make any sense.  It should be a closed system with the only openings being the gas cap and the injectors.

 

Dropping the tank in your driveway will be a PITA.

 

I did a little poking around and found this:  https://www.facebook.com/groups/fordedgeforum/posts/2803331423198293/

I am not a Facebook User but it looks like it may contain the info you may need.

 

An AI response produced this:

Edited August 22 by Samurai Edge

[ClaudeButler]

 

Samurai Edge said:

I would think there should not be any leaking at all from the gas tank, but that's me as it doesn't make any sense. It should be a closed system with the only openings being the gas cap and the injectors.

Dropping the tank in your driveway will be a PITA.

I did a little poking around and found this:

I am not a Facebook User but it looks like it may contain the info you may need.

An AI response produced this:

Edited August 22 by Samurai Edge

 

Yep, the EVAP system should be sealed, but it still has the vent side/canister/lines in addition to the filler neck and purge side, so a small leak or restriction there can definitely confuse the PCM and throw purge-related codes.

 

And I agree, dropping the tank in the driveway is not fun unless you’ve got the space, jack/supports, and patience. Before going that far I’d want to smoke test the EVAP system and verify the purge valve is actually OEM and sealing properly. That Facebook post may help, but if anyone can’t view it, maybe paste the relevant details here so it’s not locked behind Facebook.

[Samurai Edge]

As I stated, I'm not a Facebook User.  I only provided the link for those who may have access.

 

Social Media sites like Facebook, etc. are definitely not my thing.  I don't venture to those places.  They may have been a good thing when they started but unfortunately they have devolved into, well . . . .  I don't really have to say it because most intelligent people already know.

[STBEAST]

Samurai Edge, intelligent people do not need to use social media. That is a given I too have avoided the social media monster that eventually consumes so many people lives. 

We are probably missing out on some valuable and helpful information. But at a cost for sure. 

As I make this post on this social media website. I realize to some degree, I have been consumed by the lonely, biassed, sad social media monster.