Sporadic idle, vacuum leak?

just finish rebuilding the engine in my 2.7L 03 Tacoma. It has an idle problem, it runs idle at 2,000 RPMs I found a nick in one hose and replace it, but now after I drive it around when I come to a stop it wants to jump from 2K down to 1K and immediately back up to 2K. It was doing it every so often but now it’s doing it constantly. Was told it’s probably a vacuum leak, i cleaned the IAC valve and throttle body so that’s not it. Any idea where this hose/T is supposed to go to? The short 2” hose was clogged with mud and I cleaned it out. I tried plugging it to see if that made a difference but it doesn’t.