CJF said:
can't speak with complete certainty and purport any type of knowledge I may not have in this subject,but...
When my 02s went to the crapper I didn't realize even a 100 rpm idle difference.
That said, I'd go to the TPS, the throttle body, check ALL of the vaccum hoses-particularly follow those with their home on the top of the air cleaner can, shoot! buy as many feet of vaccum hose as you can afford and replace the worst hoses anyway-you will be amazed at the "smoothness" change in the engines idle. Also check throttle cables (all as mentioned before), and check timing and valve clearances.
I went through this whole list (minus the 02s till they crapped) as well as wires, plugs, and dizzy rotor/cap when I puchased mine-made ALL the difference.
Lastly, check the yahoo 3fe list-or search on birfield.com (again...as already noted)