I have a 2015 Impala with almost 18,000 miles on it now. The last week I have noticed that anytime the transmission goes from 3rd to 4th gear the rpms rise by a few hundred before it will switch. This causes a delay in switching gears. It will do it no matter how I accelerate. I have the trifecta tune but don't think this is the cause as it will still do it when I engage cruise control(tune off). Am I the only one experiencing this issue?
PS. I have the 3.6l v6.
PS. I have the 3.6l v6.