Just an fyi.... removing that rubber seal/boot from the original one stretched it out for me. I was very careful in the process but I still got evap codes with the new one in place. I took it off again and wrapped a couple of layers of teflon tape over the rubber seal and the other tube connector as well then installed again. This seems to have fixed it for me. The gas cap warning popped up first drive after install before the teflon and then 446, if I remember correctly shortly thereafter. I searched far and wide for a new rubber seal or for a solenoid with one but they are not available as far as I can see.

I know this is an older thread but maybe this might help someone out.

That rubber might just be a failure point. My original install seemed to wiggle a bit and I wondered about it. You might try just blowing out the solenoid and using teflon tape before buying a new one.

 

I recently used this thread, and others to diagnose and repair my 08 SS. I now have new Solenoid Valve, Purge Valve and Gas cap. I found power at the harness initially so started swapping parts to solve. None worked, took inner fender well out to check the vent tube at the filler neck, this is a hard line so don't waste your time unless in a wreck. finally pulled harness at bulkhead to Solenoid valve. Tested red wire = good, tested white wire = not good. About 2" back from small plug someone had used pointer on test light and all but broke the wire, then it corroded over time and broke recently. Anyone need some used parts(cap, SV & PV) can have them just pay S&H. Or local pick up.

 

The seal in the port above my thumb, pointing to the left.

I just used this thread to determine what this was, well DUH, it’s that oring .

 

mine does not have that rubber seal. It only has 0-ring

 

Problem found.

 

Where do you get that at?
Here is what mine looks like.
https://www.ebay.com/itm/GM-OEM-Vapo...gAAOSwRoZZgDKQ

 

Oldblue said the rubber seal is the o-ring. You said you have the o-ring, but not the rubber seal. Hmmm...

 

From the first post.....

5) take rubber seal off of old solenoid and place it on new solenoid.

 

Mine had a soft O-ring that was in the canister hole.

 

When I did mine a couple of years back I looked at the new one vs. the old one and noticed the missing rubber piece. Wasn't a new one in the box so I salvaged the old one and never had an issue. I hadn't read this thread at the time, I just try to notice stuff like that.

If the old one were damaged or the solenoid tossed without salvaging the part it's probably time to match something up or see if you can find one at a "pick a part" place. Or you could see if hellshotrod has one. It may not be something readily available new from GM.