My car will idle around 600-650rpms, and then every once in a while it dips down to 300rpms and shakes and almost stalls before catching itself and going back up.

Any ideas.... IAC, EGR, o2's, I have no CEL.

Tomorrow im going to hook it up to a scan tool and I hope to catch something...

 

have you cleaned you intake? that did it for me.. it is really easy to do just take off box or cai and scrub and spray cleaner in sider MAF sensor... you will get alot out.. cleans up the running of the car...