LMG to L9H swap ecm questions

[MarcoPolo81]

First post (maybe 2nd) and Newbie to the swap world PLEASE HELP!!! Sorry in advance for asking a LOT of dumb questions.

My questions are mainly about the ECM along with codes P0172 P0175 & P0521

What does the ECM on the gmt900 platform do?

Did swapping the engine going from a 5.3 to 6.2 cause the rich codes?

Does my 2010 5.3 OEM ecm have to be re-flashed since I swapped in a L9H engine in the place of the LMG engine?

Does the ECM learn or recognize the L9H engine change because my engine didn't come with the ECM?

Can I use an ECM from a 2010-13 Escalade even though it has AWD and I have 4wd/3.42?

Will the dealership re-flash the ECM and how much do they charge? I was told that I need to have some specific info handy. Can anyone shed light on what info I would need?

Any feedback would be greatly appreciated.

 

[Geotrash]

@ls1frc

 

[LARRY M VANDIVIER]

How hard is swaping a 1999 yukon 350 vortec to a 5.3 04 model with different harness setup and ecm...

 

[swathdiver]

@Squirrelsmith Look up Kevan and send him a message. Looks like he hasn't been on in a while, not since the swap, must be out driving it!