So I watched a lot of videos and I found no matter the make but I'm having the same problem on the same truck. I'm almost certain it's the green wire that goes to the evap sensor gets corroded and needs to be re wired this is why you don't have to drive 60 miles before the code appears because an electrical problem will show up immediately after the second start hope this helps.

 

Do you go into limp mode when P0446 code pops up? My truck keeps going into Limp Mode as soon as I go from 1st to second gear. I'm trying to figure our what's going on.

 

1. Start your own thread.
2. Include vehicle information.
3. Scan YOUR truck for any fault codes IT may have.
4. Don't necro-post with insufficient information or unrelated issues.

No, the usual causes of a P0446 will NOT cause "limp mode".

 

yes all the videos I've seen and asked around to a couple mechanic buddies back in CO, it ends up being the green wire and ot just on ford, heyve seen it alot lately on gmcs and chevys. so I'd go with replacing that green wire.

 

Did you find the solution?? I'm going through the same exact thing

 

Replaced about a hundred vent valves at the dealer back in the day
Do the pinpoint tests for code P0446 in the PCED

 

Is P0446 the only code you're getting.

From what I've read the first thing to check is the wires at the cannister vent valve. Are its wires free of rust and corrosion?

 

Dropped the spare tire. Pulled out the vapor canister vent valve replaced it with a new valve CEL gone. Auto Zone had it in stock 117.00 plus tax. 2 hours to do the job.

 

Good to hear. Thanks for the update.

 

Those of us in getting the code in 2026 thank you as well.