I have a 99SE 5 speed, and I ordered an IAC valve from Courtesy Nissan (I got the PN from the forums here, 23781-38U05). When I received it, I found that it is a little different from the old one. The main difference is that the new valve has 2 extra solenoids on it (my Haynes book says one is for power steering, one for A/C) that bump up the idle. My old valve just has one extra solenoid on it (the power steering one according to the Haynes drawing), and the other is capped off with a screw-in plug. The Haynes book makes no mention that one solenoid might not be there. I installed the new IAC anyway, and it seems to be OK (it cured my erratic idle speed for sure). I assume that the second solenoid was missing from my old valve for one of 2 reasons: 1) a redesign to eliminate it, or 2) maybe a difference between automatic vs 5 speed. Does anyone know about this one vs two deal? Also, I have nothing to connect to the second one, but I assume it will just stay closed that way (as good as capped off). Does that sound reasonable??

 

The IAC valves on the 95-97's are different from the ones on the 98-99's.

 

So whats the part number for 98-99? I need to order one.