2001, Tacoma, regular cab, manual, 2.4l.

I've been trying to fix my high idle problem lately. I have no CEL or codes. At first startup, the engine will shoot to 1500-2000 rpm's then settle at about 1200. After a couple of minutes, it will reach 1000 and stay there for a while. Sometimes when it's warmed up it will come down to 850 (it is supposed to be 750 + or - 50). 

I cleaned my MAF and IAC. This didn't help. I checked my TPS, MAF and ECT according to the Factory service manual. They seemed fine.

I have a Blue Driver OBDII scan tool. I used it to watch MAF, fuel trims and o2 sensors. The MAF seemed to work properly and the fuel trims looked to be ok. My long term was pretty steady at +0.8%. Now is where things get weird. My upstream sensor stays at a high voltage all the time and just barely moves with the throttle.

The only thing I know to do is replace the IAC and the upstream o2 sensor, see if this fixes the problem and work from there.

Below are four videos of my o2 live data.

     The first video is just idling.

     The second is idling with some blips of the throttle (when the o2 sensors' readings change).

     The third is running at 2000rpm steady.

     The fourth is idling then bring rpm's to 2000 and holding (when curve shoots up then gradually comes down).