The Evap.system is not very complicated. It consist of An Evap. Canister, Leak detection pump, Purge solenoid, Vac. lines and a Fuel cap that you've just replaced.. If the Problem is a Leak, the easiest place to start is under the hood by the Brake master cylinder area on the fender well. The component your looking for is whats called a Purge Solenoid. See Fig.1. The solenoid will have multiple vac. lines connected to it. There are several splices of rubber hoses to a molded plastic lines. Check all the lines for minute cracks. Pay close attention to the rubber sections of the lines as you check them. The Evap. system can detect vac. leaks up to 0.020Hg of vac.. If the rubber splices have small cracks around them , you can replace it with the same size hose from a local parts store thats marked emmisions on the hose. Cut to size.. follow the vac. lines and check it as you go on. once you get to the line thats routed under the veh. this is where its going to get a little more difficult to check. The Leak Detection pump solenoid and canister is behind the fender on the left rear . let me know what you find on your end first from what i've given you to check.
