2000 2.4L idle speed suddenly too high...?

[automan9482]

2000 Tacoma SR5 XtraCab, 2.4L, 5-speed, 2WD, 133K miles.

Hello all, hoping someone can point me in the right direction with this.
I recently had my truck out of service for about 3 months while trying to locate a hard to find rear axle shaft/hub assembly. About 3 weeks into parts hunting, I realized it was going to take some time, and took some measures to store the vehicle in the interim. I added the prescribed amount of Stabil to the gas left in the tank (at the time it was about 1/16th under half a tank,) let the engine run for about 5 minutes after that, and then disconnected the positive terminal of the battery.
About 2 weeks ago I was able to put the truck back on the road. All repairs were satisfactory, but now the engine idle is off, and I don't know why.
Before storing it, the idle was always right around 750 RPM, which is normal according to the repair manual. Once the battery was reconnected and I started driving the truck again, the idle has been staying around 1,250 RPM.
I hoped after a few miles the ECM would "relearn" its parameters and the idle would correct itself, but it has not.
I drove out the half tank of gas that had been left, added just over a half tank of fresh gas, and have put over 200 miles on it since but it still is idling too high.
I did a diagnostic scan, even though there is no MIL (Check Engine light.) There are no codes saved, and again, no MIL. I even pulled the main EFI fuse in the underhood fuse block for more than 30 seconds to try to reboot the ECM, per the repair manual, but that did nothing as well.
The high idle is moderately annoying, at best, and is also hurting my gas mileage...

Does anyone have any experience with this issue? Any suggestions?

Many thanks in advance.

[G-man422]

It may sound silly, but did you check your air filter and box? Sometimes while in storage mice will build homes in there. It could be throwing off your amount of air to the engine. Just a guess, but good luck.