so I purchased a t2 awhile back and had a 2010 challenger hence no pcm needed but I traded it in for a 2017 now so how can I go about getting a pcm for the 2017 and for that fact will the same tuner work with it (I reset factory tune before trade in)

I have a 2010 challenger 5.7, What is the difference between the 91 tune and the diablo tune. I started with the 91 ran fine switched to the diable tune and on WOT it started to backfire and reported 14 on knock so I shut it down went back to 91 wondering why it runs so awful on the diablo tune