Ive had some issues with rough idle warm, in drive on my 99 obw. New plugs helped. Also found a loose fender mount that was rattling, but its still kinda rough. I picked up a iac valve at the junkyard, going to clean it and just got the new gasket in. It looks like both temp sensors are easy to get at with the iac out. Since the sensor controls the iac via the ecm, is it a good idea to change this also? Is this another case of " use only oem" sensors? Looks like the aftermarket 2 wire sensors run from 60$ to 15 on ebay. Anyone use these? What do you guys think? Maybe just leave them alone? Also, ive read the threads on iac cleaning. Was thinking of soaking in gasoline and q tips? Anyone have experience cleaning one of these?

dont know about the 99 version - but just did this with my 90 Legacy

 

used carb cleaner, a little brake clean, and rinsed it all out with seafoam

did use a few Q-tips to break "scrub" loose the stubborn stuff.

 

hope that helps