94 SW2 sputtering problem

Hi all,

I just bought a 94 Saturn SW2 and it runs great except that I noticed
that it sputters (like it is getting differing amounts of gas) when I
have light pressure on the accelerator. When I am coasting it is fine,
and when I give it moderate to heavy accelerator pressure, it runs
smooth and fine, but when I am trying to maintain speed, it is
sputtery. I have no maintainance history for the car, so I am changing
the oil, fuel filter, air filter and PCV valve. Has anyone had this
problem or knows specifically what it is? It is a 5-speed manual, and
it doesn't matter what gear I am in except that I sem to feel it more
in the lower gears.

Thank you!

Gary