I am honestly dumbfounded on this error. I am getting a P1450 but primarily when its cold in the mornings.
if I clear it it could be gone for weeks or a month or just pop right back up.
I replaced the purge valve and it fixed it for a while but its back again

 

You could have a clogged charcoal canister or a kinked line somewhere

 

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But if it was a clogged canister or a kinked line wouldn't it show up all the time? or am I not understanding correctly

 

Try changing out the EVAP Canister Vent Valve, It could be sticking when cold.

P1450 - Unable to Bleed Up Fuel Tank Vacuum

Possible Causes:

• EVAP purge valve stuck open
• Blockages or kinks in the EVAP canister tube or EVAP canister purge outlet tube between the fuel tank, the EVAP purge valve and the EVAP canister
• Capless fuel tank filler pipe damaged, preventing vacuum relief (if equipped)
• Contaminated fuel vapor elbow on the EVAP canister
• Restricted EVAP canister
• EVAP canister vent valve stuck partially or fully closed
• Plugged EVAP canister vent valve filter
• VREF circuit open
• Damaged FTP sensor

 

I have been troubled with this code P1450(unable to bleed fuel tank vaccum) and still have not found a solution. I have changed the purge flow solenoid as well as the vent solenoid attached to the charcoal canister box. Forsccan data shows 3D 81(blocked evap system line-fault confirmation test) not ready, and 3D 82(vapor blocking valve perfromance) not ready. For some reason it is never able to test. Any idea of what you think can be causing this? I have a 2016 ford f150 5.0. Thanks so much!

 

Just a update the error is on all the time now. its no longer a tempature thing.Does that change anything?

 

Did you do what was suggested in post #4?

 

sorry for the delay had some craziness here. yes I have replaced both items.
the one on the charcoal canister was a turd to get back on but I did it.
I cleared the codes with a code reader and the negative battery and it came back. any ideas from here

 

how would I locate a kink or know if the canister is bad?

 

any help would be great