Sup guys..
Just wanted to share my experience after cleaning my throttle body and give some helpful information about the "Idle Relearn Procedure".

I recently adjusted my valves on my 2007 MDX with 102K the valves were OK but I had a small carbon build up in my Intake Manifold and TB which I proceded to clean thoroughly. Soon after putting everything back together I started the car and was greeted by a 2000RPM high idle which I assumed was because I had disconnected the battery, after going through the infamous "Idle Relearn Procedure" 3 times my Idle would simply not go down like it has to. So I went for a drive and soon after the CEL went on. 2 codes stored: P0507 and SH-AWD:77.

1.- SH-AWD: 77 was discarded as I know this is a generic code for SH-AWD deactivation because of a 3rd party issue. In this case was an Emission Code: P0507.

2.- P0507: "Abnormal Idle Speed Too High" this code is not very precise on what is wrong, Basically the ECU is noticing the Idle is too High for any given reason. It could be a vacuum leak or it could be a failing Throttle Body, etc...

So what went wrong?
The issue relies on the fact the "Idle Relearn Procedure" is Step 2 of resetting the idle speed.
Before doing the "Idle Relearn Procedure" Honda says the "ECU must be reset" but its not as simple as just disconnecting the battery.. Honda/Acura actually wants you to reset the ECU parameter: "TPS Position". This cannot be done by any other way than using a GOOD OBDII Scanner that can read OE Data (Not just OBDII Information), In the case of Honda its using the fancy "HDS" Scanner.

What caused this?:
When the throttle body starts to get clogged up with carbon the ECU will "Adapt" the Idle to the carbon build up restriction, This means the TB Blade will set its resting position higher and higher to maintain the correct factory idle. When you clean the carbon build up there is suddenly more air than expected at the set resting position meaning the car is sucking too much air at idle which lead to a High Idle Situation.

According to the Honda Technician you can also disrupt the TPS data by simply opening the TB Plate by Hand! Which will need the TPS to be Reset!

So what about "Idle Relearn Procedure"?:
The "IRP" does nothing more than to accelerate the ECU adjustment to the previously SET resting position.. This means that if the ECU has already adjusted the Idle because of carbon build up the IRP will only relearn that position faster than letting the ECU do it automatically.

For example:
If the FACTORY RESTING POSITION is 1 out of 10 (Example, the correct measurement is in °angles)
The ECU corrected carbon build up resting position is 3 out of 10
The IRP will only set the idle back to 3 out of 10 because that is the ECU Set resting position

So how the ECU gets the TB Resting Position back to 1 out of 10?
The only way is by resetting the "TPS" this will force the TB to return to factory 1 out of 10 position.
This can only be done if the TB is fully clean as any carbon build up will create an unmetered restriction causing the Idle to be too low at factory resting position.. If you just remove the TB and do not mess up with the Blade you can do simply the "IRP" which will return the Idle to the last ECU Set position without any issues. The ECU however cannot reset the TPS position by itself meaning that the ECU cannot by its own means go back to position 1 out of 10 it has to be manually reset after cleaning the TB.

HOW DO YOU FIX IT????!!!
1.- Get a good scanner that can read OE data and can perform tests.
2.- Connect the reader and reset the "TPS" data this will cause the ECU to set the TB back to factory resting position (Make sure the TB is CLEAN).
3.- Do the Idle Relearn Procedure this will set the Idle to factory ECU Spec.
4.- DONE! You will now have the correct idle.

HOW CAN YOU PREVENT IT??
You can't If you have carbon build up, odds are the ECU has already adjusted the TB Resting Position by itself meaning you have to reset the TPS.

If you have very low carbon build up and think the ECU hasn't self adjusted? According to the Honda Tech you can open the TB mechanically by setting the Key in Position II and flooring the car.. This will open the TB and allow you to clean it with a Rag that has been soaked in carb cleaner! *Never spray the cleaner on the TB itself! Honda does not want you wash out the grease on the TB Blade bearings.

So now you know it!
If you clean your Throttle Body or Simply open the TB Blade and get a P0507 + SH-AWD:77? Odds are you need a TPS Reset + IRP.