Why wont my Tundra 4.7 V8 idle after I re-connect the battery?

Today I used some MAF sensor cleaner to try to chase away a P0101 CEL. I unhooked the battery purely as a precaution. Now I wish I hadn’t done that.

This is the second time I’ve disconnected the battery. Both times, the truck went from running fine to (post battery re connect) wanting to idle around 450 rpm. That’s not enough rpms for the alternator to make 14 volts....

The first time it happened I drove it around for an hour - hoping it would re-learn- and nothing changed. A buddy brought his SnapOn OBD scan tool and did a “zero point” reset. This is a 2006 Tundra with 252k miles and the 2UZ-FE engine  

So now it’s doing the same E36 M3 and I’m frustrated. WWGRMD?

Here's a discussion that shows a DIY approach.

I'd actually written up a paragraph or so about how I'd google for what zero point reset meant, and was assuming it'd have something to do with throttle position, and perhaps the truck looking for a default TPS value that didn't match reality until you tell the truck "this is where the throttle is at closed throttle", and perhaps you could adjust the TPS to match whatever's in the ECU for a default after a battery disconnect.

Then I looked and everything zero-point-Tundra-related talked about this steering issue. Which really confuses me for your idle issue. I have no idea why that would be related. Do you have more context? Is there more than one zero point reset, and could TPS be a different one that's just less discussed and thus hidden in the search results?

Last time this happened after I replaced my steering wheel (disconnected battery because airbag) with the truck parked on a slope. After reconnecting, the computer was confused and it idled super low... just like it’s doing today. That was what necessitated the zero point reset. Last time.

This time it was parked on a flat driveway when I unhooked the battery..  so I’m stumped. 

I wish there was a screw to dial up the idle...

 I don’t know if this applies to your motor, but I had a similar issue with an Impreza after changing the battery. There was a specific “idle re-learn” procedure  I had to go through, after which it idled properly.  Try Googling “Tundra idle re-learn” and see what comes up.

In reply to OHSCrifle :

Regardless of the specific symptom, worth looking into the paperclip trick, given that it's what The Internet hands out for zero point reset, and given that however odd it seems, you got the same symptom last time, also cured by zero point reset? Are you getting a CEL?

There does seem to be a fair bit of discussion around this on Tundra forums. If I owned a Tundra, I might do some more reading, but I'm going to leave that to you 

Solved. Disconnected battery again then cleaned the MAF sensor and throttle body + Italian tuneup FTW

In reply to OHSCrifle :

I was going to suggest the cleaning.  I don't understand why the Japanese have such a hard time coming up with idle speed control.  Everyone else can set an rpm, and have the idle speed control hold the idle speed there.  The Japanese argue...I've had Nissans that I've had to put a pice of cardboard over the air intake after a throttle cleaning to get idle speed down to a range so it can relearn.