1998 Chevy Malibu Rough Idle

My car runs fine cold, and starts imediately when it's cold, but when it warms up becomes harder to start and starts to idle rough but it is off and on, they aren't long intervals between each time it gets a rough idle it's literally no more than every second. But then sometimes at a stop light it won't do it, but most of the time it does it. It has new coil packs, plugs, and wires. It isn't a horrible idle but it is enough to make me worry. Also when the car is at idle and I rev it a little, when the RPMs come back down they will fall lower than the normal idle speed for a second and the shoot up 500 or 600 rpms by itsef but then come back down.
I also have a Air/Fuel ratio gauge in the car and when the car idles rough it will go rich off the gauge and then when the rough idle stops it will go back to normal, but there are no trouble codes on so I didn't think it was an O2 sensor.

Thanks for your time!