If you want to disable the sticky header in #emporio Blogger theme, add the code below to your blog html :
.centered-top-container.sticky {
position: inherit !important;
}
OR
search your blog html for the code below :
<header class='centered-top-container' role='banner'>
<b:class cond='data:view.isSingleItem' name='sticky'/>
<div class='centered-top'>
and change the “sticky” to “sticky1”
You can also try this of you want to disable the sticky header in the other new Blogger themes.
Kindly let me know if it works for you.