Tighten gas cap

[Skipper50]

hi all,

Everyone was so nice after my “vent” post I would like to ask for help. I have a 2015 Tahoe LTZ and for the last year I get tighten gas cap on the DIC and I dismiss and it comes on a few days later then after the 3rd time the check engine light comes on. I have purchased a new gas cap and Chevy has done a smoke test and a vacuum test and they say everything test ok. On a scanner it’s code P0445. Without replacing every sensor and solenoid has anyone had this and figured it out? Thanks for your help.

Had this summer before last on Yukon XL.
Canister vent solenoid was the culprit.
Location at the rear undercarriage allows for crud entering the vent.

 

[Rdr854]

If it’s the canister vent solenoid, would it not be covered by the emissions warranty?

 

[Kaygeez]

I changed these parts on my 15 Yukon and it fixed that problem:

https://www.rockauto.com/en/moreinfo.php?pk=8917496&cc=3307644&jsn=479 (but got AC Delco. Also, its located right by the gas cap)

https://www.rockauto.com/en/moreinfo.php?pk=6401292&cc=3307644&jsn=482 (Located in the engine bay near the MAP sensor)

 

[KVacek]

On my 2005 Yukon Denali XL I changed the vapor canister vent solenoid first based on a recommendation. Under the car, hard to get the hose off. When that didn't change anything I replaced the vapor canister vent purge valve under the hood. Easy to do, still didn't fix it. Finally replaced the gas cap and still no resolution. Used Delco stuff from Amazon, figured it must be something else.

Then I learned that the cycling necessary to reset this code itself requires warmer weather. It was winter when I did this and I'm not sure if the car ever got warm enough to reset itself. Having already replaced all three potential defective components, I reset the code with my reader and it never came back. I thus don't know which component caused the issue, but on the theory that overfilling the tank could harm the vent solenoid (I used to coax every last drop into the tank on every vehicle), I now stop filling when the pump kicks off the first time. All has been good for years now.