It does exactly what I bought it for
I bought this to turn off the afm on my truck and it does exactly that. I have also been able to read an engine code with it already as well and worked great. The reason for 4 stars instead of 5 is because it seems to mess with the truck electronics while installing the tune (dash lights flashing, service stabletrak), which I don't know if its normal or not but worries me, so I will just stick with the stock tune with the afm disabled. Autoanything was extremely helpful with the purchase.
Surprised by how well it worked.
Used on my 2017 Silverado Crew Cab 5.3 4X4. I installed a cold air inductions intake & installed the performance tune with 93 octane. Immediate difference! Pulled harder, sooner & with the intake growl, it sounded amazing. Noticed maybe 1+ additional mile per gallon with the performance tune. Now while using the mileage tune, I could tell it didn't have the additional punch as before, but the mileage was slightly better at an additional 2mpg. Wish there was an 89 octane tune as well.