Заменил в sql запросе сортировку
$sql = 'SELECT p.*, product_shop.*, pl.* , m.`name` AS manufacturer_name, s.`name` AS supplier_name
FROM `'._DB_PREFIX_.'product` p
'.Shop::addSqlAssociation('product', 'p').'
LEFT JOIN `'._DB_PREFIX_.'product_lang` pl ON (p.`id_product` = pl.`id_product` '.Shop::addSqlRestrictionOnLang('pl').')
LEFT JOIN `'._DB_PREFIX_.'manufacturer` m ON (m.`id_manufacturer` = p.`id_manufacturer`)
LEFT JOIN `'._DB_PREFIX_.'supplier` s ON (s.`id_supplier` = p.`id_supplier`)'.
($id_category ? 'LEFT JOIN `'._DB_PREFIX_.'category_product` c ON (c.`id_product` = p.`id_product`)' : '').'
WHERE pl.`id_lang` = '.(int)$id_lang.
($id_category ? ' AND c.`id_category` = '.(int)$id_category : '').
($front ? ' AND product_shop.`visibility` IN ("both", "catalog")' : '').
($only_active ? ' AND product_shop.`active` = 1' : '').'
ORDER BY p.`price` ASC , p.`quantity` ASC LIMIT '.(int)$start.','.(int)$limit : '');
Было:
ORDER BY '.(isset($order_by_prefix) ? pSQL($order_by_prefix).'.' : '').'`'.pSQL($order_by).'` '.pSQL($order_way).($limit > 0 ? ' LIMIT '.(int)$start.','.(int)$limit : '');
не работает(((