I have a 2000 Si with the b16a2. The car idles about 1000 rpms which is another issue but when in motion or sitting still at 16-1700 rpms the cars idle will bounce. Could this be an issue with my tps or something else?

 

I am going to replace my IACV soon and see if that fixes the same issue for me.

 

sounds like a possible bubble in the coolant. flush it, and refill it.. if its still doing it, let me know, i've got another suggestion also, but flushing/refilling the coolant fixed it for me, but my buddy did some other stuff, and it fixed it.