Thall12, as the Wiz has said, several things can cause the flavor to drop off. The most common thing is a clogged or dirty atomizer or cartomizer. You will notice a loss of vapor also and the draw will become tighter.
Try replacing the atty or carto with a new one.
Also, insure that you have plenty of
juice in the cartridge or carto. A dry one will also cause loss of flavor.
And, last but not least, clean the connector on the battery, then charge it up fully.