Replaced the vent valve because the truck was filling very slowly and the check engine light code P0446 said that was the issue. Check engine light was reset and is still out but tried to fill the truck and same issue occurred. This is a 2015 Chevy Silverado high country 4x4 with 74600 miles on it. Any suggestions would be appreciated!

 

the tank vent path is: the tank to the cannister...out the vent valve to the vent filter...this entire line must be clear.

i would disconnect the line from the tank to the cannister...do a refueling event. if it fills properly...replace the cannister and cannister filter. blow out the lines from the cannister to filter.

 

I went through fixing this exact code a month ago on my 2006 Silverado 1500 work truck. I had to replace the EVAP vent solenoid and canister, which was hanging off the side of the gas tank near the spare tire. Pretty sure you can kill these things by overfilling the gas tank up into the neck - something I will be cautious of going forward.

Be aware that while you can go to about any auto parts store or rockauto.com and get the canister/solenoid combination cheap (under $30), if your 2015 uses that same plastic type hose that my 2006 did, the hose is not reusable, and the part WITH the hose attached was $100 more. My solution was a couple of feet of 5/8 inch hose, clamped at each end.

 

I replaced the vent valve that is what the code said to do, it's the long hose type thing with several components on it. So I understand I may have a few more components
to replace?

 

No it didn't. Diagnostic faults are not shopping lists, and NEVER, EVER tell you to replace something. They simply inform you of an unexpected condition. It's up to you to find the cause of condition through testing and troubleshooting.

Throwing the parts store at your problem is a great way to empty your wallet and never find out what the actual problem is.

https://www.obd-codes.com/p0446