How to diagnose tank fuel pressure

[treehan77]

Already changed: Evap vent valve, canister, purge solenoid and blew out lines (tons of pellets).
Now getting p0446
My ELM327 and program only seems to show PID for fuel tank pressure as mmHG, can’t find a voltage. What should this reading be? It seems like it’s -0.33 mmHg at standstill. Am I correct that this means vacuum? Removing fuel cap, no whoosh sound, no reading change. Is there any way to test with what I’ve got? (Can’t Carla or open system with it, it’s just a cheap scanner)

 

[Scottydoggs]

https://www.samarins.com/diagnose/p0446.html still got a blocked line would be my guess.

were you able to remove the hoses and blow them clear, or did you do the blow in the tube and hope it all blows back out deal? if you just blew air in the closed ended hose, id take it all the way off and try to clear it more.

 

[treehan77]

After a drive, I was able to see the tank pressure varied from -0.8 inHG to 32.2 inHG. Is that seem about normal? Realized I had it in metric mode lol. Yeah, I could only blow into the lines.