This is actually a fairly common fail item on these vehicles. The most common fail item is the Evaporative Emission (EVAP) vent Solenoid. Inspect the wire harness for any broken or loose wires. Inspect the vacuum lines for holes of disconnections. If the visual inspection checks ok, suspect a faulty solenoid. It's located under the vehicle, near the fuel tank.
Here's another view that may give you a better idea of it's location:
Everything looks fine, apparently solenoid is a dealer only item will have to pickup next week
Yeah- unfortunately, this is Dealer item only. Most "emissions" related parts are. Like I say, very common fail item. Sometimes its the solenoid itself, sometimes the tube gets clogged. Either way, have to buy the whole assembly.
Don't forget to remove the "NEG" cable prior to the replacement. This will clear the codes in the computer by the time you are finished with the job.