I have noticed that when i pull out on the hwy as its in 1st gaining speed it shifts really quick to 2nd and about 35-40 mph it downshifts to 1st and then back to 2nd as it gets faster ! It does have 4.56s and 35s with stock pcm ! Has anybody else experenced this ?

 

When's the last time fluid/filter were changed? Might wanna adjust the bands as well.