99 Cavalier hesitating

I have a 99 cav that often hesitates while driving. If I put it in neutral, it only revs to about 4500rpms and falls back and fourth between 3000 and 4500rpm. I changed the fuel filter but nothing changed. Any suggestions?

Check out the fuel pump recall here: http://www-odi.nhtsa.dot.gov/

Cheers