viewing the output buffer

OK. After over a month of trial and error and banging my head against the wall i figured it out (or a workaround). I now use:
           header('Content-type: application/json');
           header("Access-Control-Allow-Origin: *");
           echo ($json);

instead of

  $this->output
      ->set_content_type('application/json')
      ->set_header("Access-Control-Allow-Origin", "*")
      ->set_output(json_encode($table));

proof that an old dog can learn new tricks