All excellent advice, and it should be checked first. Fouled plugs, and just about everything else will affect idle on these. THe o2 sensors won't cause this problem, but will cause the plugs to foul.
Dont overlook the PCV valve. Aftermarket PCV vlaves can be "close" and not quite right, even if the parts book says it's right. Very touchy. The slightly out of calibration PCV can cause the problem. In reality, a PCV valve is a calibrated vacuum leak. A factory valve could be worn out causing the problem as well.
If these fail. check the ignition timing. Advanced timing will create a fast idle that computer idle cannot overcome. Be sure to disable computer timing control before adjusting the timing or even checking it with a light, or you will be off.
Next thing to check is the minimum air settings. These should be correct, but often are not quite right from the factory. The minimum air screws should be sealed, and a plug removed to access them in some cases. It appears to be a idle set screw, and each throttle body has one. First, plug the air intake to the Idle Air Control (IAC). This will bring the idle down to a minimum, if not you missed something listed above. If the engine is now at spec, good. If not back off the screws until they do not touch, then run them in to just barely contact. Now turn both screws an equal amount until the correct base idle is reached. Now you must balance them. On the top of the throttle body there is a small port that you can put a vacuum line on the unit. It must be able to read in inches of water. If you have an manometer even better. Adjust the screws until the vacuum is EXACTLY even, while maintaining the minimum idle speed.
There, they are balanced. Remove the plug from the IAC inlet, and allow the engine to idle normally. If you still do not have a proper idle, you could have a bad IAC motor, or one clogged and dirty, with poor action and a restricted passage. Dont forget to clean both throttle bodies.
IF your idle is still off, you missed something in the first group of checks, or you have a computer problem, but that is very unlikely for this issue. Make sure all of the power supplies and grounds for the computer are good.
Fully warm is 195 degrees, but anything over 160 will work for this procedure. Keep in mind that is what the computer is reading, not actually temp, though they should be the same thing.