login menggunakan akun google pada CI

Controller :

 public function create_google(){
		include_once APPPATH .'third_party/google-api-client/Google_Client.php';
        include_once APPPATH .'third_party/google-api-client/contrib/Google_Oauth2Service.php';

		// Disini di inputkan Google Project API Credentials
		$clientId = '#';
		$clientSecret = '#';
		$redirectUrl = base_url() . 'v1/user/';

		// Konfigurasi Google Client
		$gClient = new Google_Client();
        $gClient->setApplicationName('Login ke Aplikasi');
        $gClient->setClientId($clientId);
        $gClient->setClientSecret($clientSecret);
        $gClient->setRedirectUri($redirectUrl);
        $google_oauthV2 = new Google_Oauth2Service($gClient);
		if (isset($_REQUEST['code'])) {
			$gClient->authenticate();
			$this->session->set_userdata('token', $gClient->getAccessToken());
			redirect($redirectUrl);
		}
		$token = $this->session->userdata('token');
		if (!empty($token)) {
			$gClient->setAccessToken($token);
		}
		if ($gClient->getAccessToken()) {
			$userProfile = $google_oauthV2->userinfo->get();
			// database di masukan disini
			$userData['oauth_provider'] = 'google';
			$userData['oauth_uid'] = $userProfile['id'];
			$userData['first_name'] = $userProfile['given_name'];
			$userData['last_name'] = $userProfile['family_name'];
			$userData['email_'] = $userProfile['email'];
			$userData['gender'] = $userProfile['gender'];
			$userData['locale'] = $userProfile['locale'];
			$userData['profile_url'] = $userProfile['link'];
			$userData['picture_url'] = $userProfile['picture'];
			// Insert atau update user data
			$resp = $this->m_user->user_create_data($userData);
			if(!empty($resp)){
                $data['userData'] = $userData;
                $this->session->set_userdata('userData',$userData);
            } else {
               $data['userData'] = array();
            }
			if($resp['errorCode']  == 200){
				 $stat = "SUCCESS";
			}else{
			  $stat = "ERROR";
			}
	        $count = array($resp);
	        $jsonAr = array(
	        	"_meta" => array('status' => $stat,'count' => count($count)),
	            "result" => $resp
	        );
	        json_output($resp['errorCode'],$jsonAr);
        } else {
            $url = $gClient->createAuthUrl();
		    header("Location: $url");
        }
    }

Model :

     public function user_create_data($data = array()){
        $this->db->select($this->primaryKey);
        $this->db->from($this->tableName);
        $this->db->where(array('oauth_provider'=>$data['oauth_provider'],'oauth_uid'=>$data['oauth_uid'],'email'=>$data['email']));
        $prevQuery = $this->db->get();
        $prevCheck = $prevQuery->num_rows();

        if($prevCheck > 0){
            $prevResult = $prevQuery->row_array();
            $data['updated_at'] = date("Y-m-d H:i:s");
            $update = $this->db->update($this->tableName,$data,array('id_user'=>$prevResult['id_user']));
            $userID = $prevResult['id_user'];
            return array('errorCode' => 200,'userMessage' => 'Already Registered');
        }else{
            $data['created_at'] = date("Y-m-d H:i:s");
            $data['updated_at'] = date("Y-m-d H:i:s");
            $insert = $this->db->insert($this->tableName,$data);
            $userID = $this->db->insert_id();
            return array('errorCode' => 200,'userMessage' => 'Data has been created');
        }

        return $userID?$userID:FALSE;
    }

sore semuanya butuh bantuannya nih, pada saat login berhasil masuk pada halaman login google nah setelah di allow muncul error seperti di bawah dan data user tidak tersimpan pada DB???? mungkin ada yg bisa bantu error nya :

http://localhost/api-v8/v1/user/?code=4/AAACp5G7OdLM0nKXh1XLb3M41q54e-NZKyGPkpJfZs5q4n2ePGBvrxceOC9gZytj5sUeuHo27Q-sm5NjHHPWJsQ#

{ "_meta": { "status": "ERROR", "count": 1 }, "result": { "errorCode": 404, "userMessage": "Not Found." } }