Return a 404 when a view pane in a page manager page has no result?
You can implement hook_views_pre_render in your module to do this task

/**
 * Implements hook_views_pre_render().
 */
 function mymodule_views_pre_render(&amp;$view) {
   if ($view-&gt;name == 'myview' &amp;&amp; $view-&gt;current_display == 'mypane') {
     if (empty($view-&gt;result)) {
       drupal_not_found();
     }
  }
}