Mike,
I guess I'm in the same boat. 2014 silverado 1500 6.2L. 1-2 & 2-3 shift have a delay. almost like a 1 sec defuel between shifts. this has driven me crazy for about 6 months now. If you find time, I would like to see if your improvements could correct this for me as well. I'm posting my files ...

OK,
So I did my own homework (As I should have done in the first place).

With the Intune connected to the PC:

1) a. I copied both the ECM & TCM LastTuneWritten.grg and saved under a unique name ECMCustomTune.grg and
TCMCustomTune.grg to a folder on my PC hard drive.

b. I then dropped it back ...

Want to have a couple of tunes available for mild and then wild driving options.

Some questions:

1) Can I copy the latest LastTuneWritten.grg tune off my Intune, rename it, and then drop back onto my Intune to create what I'll call a poor man's custom tune?

2) Since there is a ECM LastTuneWritten ...

Great!
Thanks for the fast reply.

Got a 2014 Silverado 1500 4x4 DC LTZ Z71 with the 6.2L.
Looking a purchasing the InTune, with custom tune package deal, but am wondering about any side effects.
Specifically, will the re-tune cause monitored info from OnStar to get wiped out (Oil change interval monitoring and that type of stuff). I ...