After the first time this happened i thought it was my tuning and not the car and tried changing some more but now that it's happened repeatedly, i'm thinking its not me. Almost every time I flash my Camaro, I get crazy amounts of knock, like 8-15*, between 2 and 4k rpm in the .6-.88 airmass areas. But I drive it again later in the day, and not a spec of knock to be found with no changes to the tune. Is this a common thing or do I need to just start and stop my car a few times after flashing it to get the ecm to settle down?