also if you recently had your battery disconnected for a few mins it may just be your ECU learning stuff over again and should go back to normal with more miles
also check that IAC bleeder screw, you may need to tighten that some
I do see two things being talked about in this thread btw
One is the act or iat or whatever you wanna call it
I have seen some say they made sure the surrounding material around the sensor itself was open to air flow of the intake tract and that made a difference as opposed to the complete sensor being positioned closed to air flow.
Just info I'm passing on as I have no data about this. btw ... I have always positioned mine ... open to the air flow.
As for the clocking of the maf ......................
You don't see that on our board too much as it is more difficult to do because of the SN95 flange mount style of maf ... which btw .... I ditched when I went to my Pro M.
Always gotta have ... most possible options
anyway ... I digress
Clocking the maf can do wonders and I have been at several dyno pulls where I've seen this done and the problem child Stang settled right down and idled like a good little boy.
Now .......... on to your hanging idle
#1 ... Welcome to the world of drivibality issues due to h/c/i
What you are dealing with is this ..........
Your pcm can't figure out what to do to help you
because
h/c/i has thrown everything beyond its ability to compensate
Short of pcm value manipulation ................
Here are a few things you can try
1 clean maf
2 clock maf
3 ensure isc is working correctly
4 ensure act is open to air flow
5 adjust air bleed on tb ... if you got one
6 adjust tb plate stop screw
NOTE: 5 & 6 kinda work together
7 ensure there are NO vacuum leaks
8 restrictor plate doo dad ... some have had positive results
Maybe some of that stuff will work for you
Here is the most important part ............. IMHO
After you make a change when trying to find a more stable idle
The pcm MAY be able to help you
BUT
It takes a while
AND
Contrary to popular belief ..................
PCM Reset is MOST LIKELY not gonna speed up the process
Resetting the pcm between changes is advisable
but still
two things gotta happen until you get the full benefit ...... if any
1 you gotta give it time to gather enough data points for those conditions
2 you gotta then give it time to make its adjustments
Bottom Line is this ................
I'd drive it around a couple of days between changes to see how much help that little silver box is gonna give you
Good Luck & This is the price you pay for .....................