My 2000 Jeep Cherokee usually runs great, however recently when i run it for a while, park it for a few minutes, and then start it again, it runs rough, has low power and will almost stall if i don't give it some gas. After about 20 seconds it dissapears, and it runs great again with no problems. When started cold, it starts and runs fine, the problem only occurs when it is warm. It seems to be happening more often, what could be the problem?

I have relatively new plugs and battery.

2000 Jeep Cherokee
4.0L V6
84K miles