engine hesitating

i have a 2002 gt and just rolled over to 60,000 miles. starting yesterday it seems to be hesitating when i go above 3000 rpms. i just changed the air filter to a k&n. would this have anything to do with it. it seems like it isnt getting enough fuel. any suggestions? any help is appreciated.
thanks
craig

Change the fuel filter and check the fuel pressure at the regulator. A plugged or partially blocked fuel filter will cause the symptoms you are describing especially at the higher rpm's. The fuel pressure regulator could also cause a similar problem but start with the fuel filter.