ЧПУ и ошибка 404

<?
$curArray = explode('/', $_SERVER['REQUEST_URI']);


if((int)count($curArray) == 4 || (strpos($_SERVER['REQUEST_URI'], '/catalog/') !== false && (int)count($curArray) == 3))
    $isSection = true;
else
    $isSection = false;

if (($isSection && $curArray[2] != '') || (isset($_REQUEST['KLEMM']) && $_REQUEST['KLEMM'] != '')) {   // проверка существования тегирования
    $arCurFilterSection = array(
        'IBLOCK_ID' => 18,
        'ID' => $curArray[2],
        'ACTIVE' => 'Y',
        'UF_TAGGING' => 1
    );
    if (isset($_REQUEST['KLEMM']) && $_REQUEST['KLEMM'] != '') {
        unset($arCurFilterSection['ID']);
        $arCurFilterSection['CODE'] = $_REQUEST['KLEMM'];
    }
    $rsCurSection = CIBlockSection::GetList(array(), $arCurFilterSection, false, array('IBLOCK_ID', 'IBLOCK_SECTION_ID', 'ID', 'CODE', "UF_TAGGING"), false);
    if ($tag = $rsCurSection->Fetch()) {
        if ($tag["IBLOCK_SECTION_ID"] != 1946){
            $res = CIBlockSection::GetByID($tag["IBLOCK_SECTION_ID"]);
            if($ar_res = $res->GetNext())
                $parent = $ar_res['CODE'];
            if ($parent != ''){
                $arCurGet = explode('?',$APPLICATION->GetCurPageParam('', array('KLEMM','SECTION_CODE','clear_cache')));
                LocalRedirect('/catalog/'.$parent.'/'.$tag['CODE'].'/'.($arCurGet[1]?'?'.$arCurGet[1]:''), false, 301);
            }
        }
    }
}
if((int)count($curArray) == 5)
    $isElement = true;
else
    $isElement = false;
?>

<?

if(count($curArray) > 5 && count($_POST) == 0) {
    CHTTP::SetStatus("404 Not Found");
    @define("ERROR_404","Y");

} ?>