Good question. I'm not a fan of using my local Chevrolet dealer for any diagnostic services, as they have refused to cover previous warranty issues.

 

With the price of gas some low life may have left his hose or what ever in there ! After trying to steal the liquid gold . Sure would not surprise me at all .

 

Dear diskullman,

I would be happy to assist you in finding other Chevrolet dealerships that you could visit if you would like to provide me with your zip code.

Michelle, Chevrolet Customer Service

 

locking gas cap....

 

I have the same problem filling my HHR The ck gas cap light comes on sometimes and also the ck Engine light sometimes comes on..Replaced the vent switch didn't help Don't know what to do next

 

Find someone who has a camera they can put down the tube to look for restrictions.

 

The most likely culprit for this complaint is the EVAP Vent solenoid and vent path, as others have mentioned, think spiders- weird but true :) Next on the list would be the EVAP Canister is internally restricted. Last two on my list would be a fuel level sensor or customer education issue, ie. attempting refueling with the key on.

The fuel level sensor because the ECM needs to be able to determine if a refueling event is taking place in order to suspend any EONV testing.