Hopefully fixed the high idle / surging problem I've been having with my car recently. Sometimes it would idle over 1k in drive and surge between 1.5k-2k in park or neutral, both only after the engine was fully warmed up. Couldn't find any vacuum leaks anywhere, no errors on ECU for a bad sensor, can't figure out wtf it is. Then when I'm rooting around I see the idle air controller's electrical connection is pretty loose (locking tab is broken, stupid brittle 23 year old plastic...), so I push it all the way back in and nothing happens, but a few moments later revs go down, then after a few more moments it goes down another step, and continues like that down to normal idle. Yay.