P04F0 code - Evap System problem

[kduff44]

Anyone else have their check engine light and check fuel fill inlet notification pop up with diagnostic trouble code P04F0?

Ford tech has replaced vapor canister purge valve and vapor canister vent solenoid but this has not solved the issue. He ran a smoke test and can't find any obvious leaks in the evap system. He's still got my truck but at a loss on what could be the issue.

If anyone has some insight or similar issues, any ideas would be much appreciated.

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[airline tech]

There are a lot of things that can cause that code, it requires deep troubleshooting to pinpoint. I would focus on the fuel fill inlet pipe as this is actuated at every fill-up, possible not sealing correctly. The self evap test puts a vacuum on the fuel tank and evap system and uses the fuel tank pressure sensor as its measurement reading.

Other Possibles:

• Incorrect EVAP system hose or line connections
• Restricted EVAP ejector connections at the intake air system
• Stuck open EVAP check valve
• Stuck closed EVAP check valve
• Damaged EVAP ejector
• Damaged EVAP check valve

 

[Friday yet?]

There are a lot of things that can cause that code, it requires deep troubleshooting to pinpoint. I would focus on the fuel fill inlet pipe as this is actuated at every fill-up, possible not sealing correctly. The self evap test puts a vacuum on the fuel tank and evap system and uses the fuel tank pressure sensor as its measurement reading.

Other Possibles:

• Incorrect EVAP system hose or line connections
• Restricted EVAP ejector connections at the intake air system
• Stuck open EVAP check valve
• Stuck closed EVAP check valve
• Damaged EVAP ejector
• Damaged EVAP check valve

Many of your posts leave me with one overall thought. "Dude's got skillz!"

 

[dtech]

usually on a newer vehicle just a bad pressure sensor

 

[kduff44]

There are a lot of things that can cause that code, it requires deep troubleshooting to pinpoint. I would focus on the fuel fill inlet pipe as this is actuated at every fill-up, possible not sealing correctly. The self evap test puts a vacuum on the fuel tank and evap system and uses the fuel tank pressure sensor as its measurement reading.

Other Possibles:

• Incorrect EVAP system hose or line connections
• Restricted EVAP ejector connections at the intake air system
• Stuck open EVAP check valve
• Stuck closed EVAP check valve
• Damaged EVAP ejector
• Damaged EVAP check valve

Thanks for the input, I really appreciate it. We will see if the tech can solve the issue and now I can speak a little more knowledgeably on the topic.

 

[Trigganometry]

Have them check in engine compartment Egr Vacuum Control - Ford (LB5Z-9J433-B)

A few on here have had the same issue and went after the gas tank sensor (got plugged from anti rust treatments) but the culprit was the above valve.

I ended up picking up a spare myself as it seems like it’s becoming a common issue.

My sons F150 had his go out on him too. Same fix.

 

[kduff44]

Have them check in engine compartment Egr Vacuum Control - Ford (LB5Z-9J433-B)

A few on here have had the same issue and went after the gas tank sensor (got plugged from anti rust treatments) but the culprit was the above valve.

I ended up picking up a spare myself as it seems like it’s becoming a common issue.

My sons F150 had his go out on him too. Same fix.

Thanks. I’ll bring that up to them. I haven’t done any anti-rust treatments so we will see if they can fix the problem.

 

[kduff44]

Got the truck back yesterday and the tech replaced the following:
Fuel Vapor Separator Tube (KB3Z-9D289-B)
Vapor Vent Solenoid (9U5Z-9F945-C)
Fuel Vapor Tube (KB3Z-9K318-A)

We will see if this fixes the issue and if the CEL stays off. At least they covered it under warranty (even though I'm outside the bumper to bumper).

 

[Loweredon33s]

Got the truck back yesterday and the tech replaced the following:
Fuel Vapor Separator Tube (KB3Z-9D289-B)
Vapor Vent Solenoid (9U5Z-9F945-C)
Fuel Vapor Tube (KB3Z-9K318-A)

We will see if this fixes the issue and if the CEL stays off. At least they covered it under warranty (even though I'm outside the bumper to bumper).

That should be considered emissions equipment, they have to fix it up to 8 years/80k or something.

 

[dtech]

That should be considered emissions equipment, they have to fix it up to 8 years/80k or something.

you have to look at the specific warranty - but some components are now only 2yr/24k miles and that could include the evap system, used to be all emissions related covered for 8yr/80k but that was changed. Some folks caught a whiff of that when EGR components failed.

 

[TremorPNW]

Did it come on after you filled the truck up?

 

[kduff44]

That should be considered emissions equipment, they have to fix it up to 8 years/80k or something.

Originally when it was just the check purge valve they said it was not covered under the emissions warranty.

 

[kduff44]

Did it come on after you filled the truck up?

No the notification was not right after a fill up.

 

[dtech]

on older vehicle small evap leaks are the most common cause of CEL - and can be expensive to locate and fix, so at the request of auto makers a lot of that emission stuff is now only covered 2/24 , some states like CO that do emissions testing don't fail the vehicle for small evap leaks as it was an undue burden on owners .

 

[mdformula350]

just got this code yesterday once I got on highway and set cruise control to 70.
after some searches it appears to be related to the fuel tank pressure sensor but now the egr vac control was mentioned first to try.

it appears at low rpms and crusing, in the past that is normally when an egr likes to be tested from previous cars ive worked on..
either way I unhooked the battery for 10 mins but the code is still there, so i guess i need to delete it instead.

2019 ranger with 58k miles, first code i have gotten.

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