Engine code PO496.

What next?

If it were me I would verify it was not closing and replace it. You might do the same thing. Miss typed earlier, Solenoid or Solenoid valve. Usually the same on GM.

Where is it located on the car and how do I verify that it's not working?

Usually attached to the intake under the engine cover. Can't say exactly right this second.

You may be right. I saw something on line about removing the cover in the engine compartment for it. What does the valve look like? Never removed the cover yet.

Find a fitting with a green cap on it and follow the plastic line back to the intake to the solenoid

Is there a way to see if it's working properly?

Yeah if you have the tools and equipment.

Thanks