Hi, I am having the same exact issue- P0496 error code and any time I get gas the car will not start without holding the accelerator to the floor while cranking. It does idle irregularly for a minute as well. Did you find out what your issue was? Was it the vent solenoid/valve?
thanks!

 

Looks like the purge canister per

P0496 Chevrolet Evaporative Emission System Flow During Non-Purge OBDII Engine Light Trouble Code | Engine-Codes.com

Part 3 in this diagram

Chevrolet HHR VAPOR CANISTER & RELATED PARTS

 

Welcome to the site.

There are two valves that can set this code.

(I'm guessing the purge valve )

1 The purge sol. Located under the hood
2 vent sol. Located under the car by the fuel tank.

The link that old blue gave you should help you figure out which one you need.

Here is another thread that may help.

https://www.chevyhhr.net/forums/how-...n-p0496-48626/

 

Yes it was the purge sol under the hood. Literally a $17 fix for the part. Now everything is fixed, no more crazy idling after refueling! Thank you for the help!
Here is the part if anyone has the same issue. You just pop this part off and plug this one in, not difficult at all.

 

Thanks for reporting back, Amelia. You have no idea how many times people come here for help, we give suggestions, and then they never report back(like the first 2 posters in this thread). Had they reported back, the community here would have learned from their experience. These data points shorten the learning curve. Glad you got it fixed!!

 

Great news you got the job done! Amelia thanks for the link!