Two different things:<p>Volkswagen (VW) cheated with its motor software and have a very high NOx emission and use a cheaper less useful catalyst in real world scenario.<p>Others have a higher NOx emission in real world scenario: Renault, Nissan, Hyundai, Citroen, Fiat, Volvo and Jeep, Mercedes-Benz, Honda, Mazda and Mitsubishi