ram2209 4/1/2010SOUNDS LIKE IT'S YOUR EVAP, PURGE CONTROL VALVE. i suggest getting your self a HAYS repair manual to find its exact location. you can get the manual at most auto parts stores.
HouseCallAuto 4/1/2010Replace the charcoal canister. It comes from Toyota with the new electrical valves. The valve gets stuck because charcoal granules get stuck in the valve. You can (in a pinch) change just the valves, the CCV and VSV (Canister Closed Valve and the Vacuum Switching Valve) but the problem will repeat when you least expect it. When you replace the canister it is imperative that you blow out all attaching lines to rid them of granular charcoal contaminant.