2004 silverado evap issue

[ole.gray]

My correction the code was p0446. Figuired out was a bad fuel tank pressure switch.

[Witsend]

P0455 is large leak.

Yep, 2004 don't seem like it was all that long ago, but for a Fourteen year old rusty SilverRotthole, that large leak could be everywhere

[Glide]

P0445 I think is code for a large evap leak.
I usually suspect either the cap is off or the canister vent (close) solenoid valve is stuck open. Should hear a audible clack on a key on engine off activation coming from rear of vehicle if it electrically working

P0455 is large leak.

[Witsend]

That is the code my ethos pro brings up. Fairly new with these scanners still trying to figure it out. Thank you for the help

P0445 I think is code for a large evap leak.
I usually suspect either the cap is off or the canister vent (close) solenoid valve is stuck open. Should hear a audible clack on a key on engine off activation coming from rear of vehicle if it electrically working

[ole.gray]

That is the code my ethos pro brings up. Fairly new with these scanners still trying to figure it out. Thank you for the help.

[Glide]

the issue i have is the pressure in the tank does not change even when fuel cap removed and the voltage does not change. still learning my scanner but feel the problem is the fuel tank pressure sensor. the code is p0445. still have a few more checks to do, just wondering if i am on the right track

I don't see P0445 listed for a 2004 Silverado in my service info.Are you sure that you selected the vehicle properly in your scan tool ?
P0445 is normally a purge solenoid fault code.

[Crusty]

the issue i have is the pressure in the tank does not change even when fuel cap removed and the voltage does not change. still learning my scanner but feel the problem is the fuel tank pressure sensor. the code is p0445. still have a few more checks to do, just wondering if i am on the right track

Go into special functions
Command the "Purge and Seal" test and watch the pressure
The Purge valve should open to draw down the system and the vent valve should close so the purge valve can draw it down.
Then with the vent still closed, the purge valve can then be closed to seal the system maintaining a vacuum

[ole.gray]

the issue i have is the pressure in the tank does not change even when fuel cap removed and the voltage does not change. still learning my scanner but feel the problem is the fuel tank pressure sensor. the code is p0445. still have a few more checks to do, just wondering if i am on the right track