// Удаляем дубли/ошибки в URL
add_action('wp', 'aks_del_dubl', 1);
function aks_del_dubl(){
    $url = get_bloginfo('url').$_SERVER['REQUEST_URI'];
    if( is_singular() ) {
        if( $url !== get_permalink())
            header('Location: '.get_permalink() );
    }elseif(is_tax() || is_category() || is_tag()){
        $obj = get_queried_object();
        $link = get_term_link($obj->term_id, $obj->taxonomy);
        if( $url !== $link)
            header('Location: '.$link);
    }
}