Rough Idle?

I have a 02 Grand Am GT with the 3.4 and 50k miles. I just changed the fuel filter, air filter, spark plugs, oil, pcv, cleaned the IAC, and put a tank full of premium gas with Lucas additive. The car seems to be running better but the engine just sounds and feels like it's running rough. The car idles at 600rpm and the needle doesn't move at all. I think my next step is the clean the MAF sensor. I was also thinking of changing the O2 sensors but those should last 100k miles and is very expensive. I guess i'm just very picky and want that thing to purr like a kitten. Any suggestions are appreciated.

yeah clean the mas with crc mas cleaner you would never believe the diverence it makes or how sooted up those sensor wires can get. As i have learned with these cars make sure you do all the simple stuff first before you go throwing money away,hope it works it did for me!

Thanks alot, i'm going to try that. I'm also going to change the trans fluid. I wish GM would've put a dipstick on there!