SES P0446

[Plati]

2003 5.4 , Service Engine Soon light came on & stayed on.
Read a P0446 code (Evaporative Emission Control System Vent Control Circuit Malfunction)

not sure what to do next
anyone have had this, any insight how to address?

quick search of the Forum shows MrHam has a post on this, will look there
https://www.expeditionforum.com/threads/vacuum-leak.43024/#post-385219

I run with no spare tire & wonder if that contributed

update: hmmm, this happened while pulling out of gas station after refueling. the gas cap says engine light may come on if gas cap not tightened correctly (see pic). i made sure the cap was on right, cleared code, and it's not coming back or pending .... yet (one minute of running).
It's possible thats all it was, but I'll wait and see before concluding.


to quote Roseann Rosannadanna ..... Never Mind

 

[RichardH]

Hey Mr. Sticker,

I think my code for similar CEL fault was P0442, but not absolutely sure.

I was driving by the dealer and my service advisor popped his computer on it and he asked if I put gas in recently. Yes.

He mentioned if the code persisted to get a new cap - picked one up from fordpartsgiant about $25. Have not had that code come up again (about 6 months ago?)

 

[bigdogchrisl]

Typically that code comes with a loose gas cap or worn out gas cap seal. These are closed/pressurized systems so even small leaks matter

Sent from my SM-N970U using Tapatalk

 

[Plati]

OK. code came back
Decided to throw $17 in parts at it, new gas cap.
Didn't fix it. Dang.

I'd like to check that wiring mentioned earlier (somewhere), gotta figure out where that is.
Don't see it yet looking from under spare tire area (which I dont carry onboard)

This says not to worry too much about driveability
https://www.700r4transmissionhq.com/p0446-ford-expedition/#:~:text=P0446 Ford Expedition&text=One of the most common,the evaporative emission control system.

Being a rust bucket ... I bet a rubber hose or metal tube has a hole in it somewhere, maybe.

Good thing I got it inspected last week, 2 months early.
Good for another year on inspection as it is ...
Still would like to fix that code. Dang

 

[RichardH]

OK. code came back
Decided to throw $17 in parts at it, new gas cap.
Didn't fix it. Dang.

I'd like to check that wiring mentioned earlier, gotta figure out where that is.
Don't see it yet looking from under spare tire area (which I dont carry onboard)

This says not to worry too much about driveability
https://www.700r4transmissionhq.com/p0446-ford-expedition/#:~:text=P0446 Ford Expedition&text=One of the most common,the evaporative emission control system.

Being a rust bucket ... I bet a rubber hose or metal tube has a hole in it somewhere, maybe.

Good thing I got it inspected last week, 2 months early.
Good for another year on inspection as it is ...
Still would like to fix that code. Dang

Did you purchase aftermarket cap (like Stent) of a FoMoCo cap? I tried a Stent cap and code persisted. Put on a Motorcraft and voila - no more code!

 

[Plati]

Did you purchase aftermarket cap (like Stent) of a FoMoCo cap? I tried a Stent cap and code persisted. Put on a Motorcraft and voila - no more code!

aftermarket
Duralast
.. maybe Autozone will take it back and I can try FOMOCO?

 

[RichardH]

Likey so on return. I used fordpartsgiant online and had it delivered. Inexpensive part to start with before digging deeper.

I also hear you on inspections. In Texas we can do the inspection 90 days before expiration - so I do it right then and there 3 months ahead. Also here they only plug into OBD2 port checking for any codes. Very unlike California where they do a visual & load test on dyno (IIRC at 15 and 25mph). It sucks because you can pass the 'sniff test' but if you fail visual you do not pass.

 

[Yupster Dog]

Did you purchase aftermarket cap (like Stent) of a FoMoCo cap? I tried a Stent cap and code persisted. Put on a Motorcraft and voila - no more code!

Same thing happened to a family member on a sport trac. Told her to get a oem cap and all better.

 

[Plati]

aftermarket
Duralast
.. maybe Autozone will take it back and I can try FOMOCO?

Autozone took the part back.
It didnt click anyway which seemed weird.
I tried another one and it didnt click either or fix the code.

I'll try a FoMoCo part and see if I'm lucky.
Tamarra or this week sometime

on another topic .... 747 won the Fat Bear competition

 

[Plati]

I got the new gas cap and it doesn't fix it. Cleared the fault and it comes back.
Oh well, it was worth a try. There are times when throwing parts at it and see'ing if anything sticks to the wall is appropriate. There appears to be an unusual strong gas smell when I take the cap off. I suspect that is telling me something but I know not what.

This BEAST is so rusted I would not be surprised if a hose was rotted, tube corroded, or electrical connection kerschnackled. This might be hard to pin down. Next I would like to examine the connection to the solenoid valve on the EVAP canister under the spare tire somewhere. Can't locate it yet. May have to look in the service manual. My guess is that electrical plug. Wild guess based on Voodoo science