You’ve probably fixed this by now, but on my 2011 V6 it was the EVAP Purge Valve behind/under the Throttle Body near the firewall. About $35. One 10mm bolt. Had to remove “accordion” tube/pipe coming off the air box, then reach around and under with ratchet using 3” extension and socket. There’s a single power plug on it, and the valve itself simply “plugs into” a bore/hole.
The 2008 is probably slightly different.