James Raskin

Im sorry if this is a duplicate i cannot seem to be able to see if my post is here from a few minutes ago.. I have been looking for a new ride for awhile and thought I found it .2016 yukon denali certified and i am finally ready to pull the trigger sitting in parking lot contemplating my purchase and I taped the peddle just because and it make a noise I know Is not normal so they bring out there gm machanic and he says its nor uncommon and is considered normal and is probably a exhaust valve or carbon build up so I did the same thing on another yukon on the lot and nothing nor on my currant 08 which is differant gen so not a good comparison . Took to a differant machanic said its internal but unsure of cause without further diagnostics. So the dealer said warranty would repair whatever it was and I left it there .now for point of this novel they said it is not valve related which is what I thought it could be but low octaine fuel so they removed the couple of gallons and ran high octaine through the truck for a couple of hours I'm curious if anyone could confirm with a good gueese if the sound in the video link is possible low octane ping as I have not heard what the sound should be if it is poor fuel. Sorry for the lllooonngg read Thank you greatly for anythoughts. Tried to insert video but am old-school and unsure if it worked.. https://youtube.com/shorts/LqQjJ22-d2w https://youtube.com/shorts/4keAqtREo3s