Codigniter 3 and php versions

Mistake:

Message: Assigning the return value of new by reference is deprecated 

Already php lowered to 5.4, still the same error, although in the CI documentation they write that you can use 5.4 and higher. An error occurs when trying to connect a class. I tried to find the line in the core of the type $inst = & new Obj(); not found.

 class Auth extends MY_Controller{ public function __construct(){ parent::__construct(); } } require_once 'Auth.php'; class Admin extends Auth{ public function __construct(){ parent::__construct(); } }