1993 Pontiac Grand Am Could it be a fuel filter problem?

When my car sits in idle and I press down on the gas pedal and then let off, the engine sounds like it revs up then down, then up and down agian on its own. It will do this for 10-20 seconds before it starts to idle normally. And when I drive between 15-20mph and let off the gas it will do the same thing unless I give it more gas then it act normally. I thought it may just need the fuel filter replaced but its not chocking and sputtering like I've heard other cars do.