Displaying custom post types by category

By using post_type parameter of WP_Query to specify all types of posts you want to get (or replace the array with 'any' to just get everything):

$my_custom_post_types = array( 'post', 'carrots' );
$args = array(
    'cat' => $Cat_ID,
    'posts_per_page' => $Posts,
    'post_type' => $my_custom_post_types
);
$cat_query = new WP_Query($args);

You’ll need to change 'carrots' to the name of your custom post type.