Get some MAF sensor spray cleaner and wash that thing down. Also check that the IAC solenoid is funtioning. If you have a PCM scanner, see where you IAC counts are running. You might also check the reading on the MAP sensor. Check these sensors for broken wires or shorts while you're at it.

bad 02s make for a bad idle but the system doesn't really read them until they get up to temp and it goes into closed loop.