A reliable engine aging method is required to screen full size catalysts for high temperature applications typical of European autobahn wide open throttle driving. Exhaust emission control catalysts will be exposed to temperatures exceeding 850C under these conditions. This paper describes one method of using an engine to rapidly age catalysts under conditions which nearly duplicate wide open throttle exhaust gas composition and temperature. The method uses a V-8 engine as a gas generator, combines and thoroughly mixes the exhaust from both banks, then divides the mixed exhaust into two equal streams, reintroduces air/fuel perturbations, and passes each equal perturbated flow through a catalyst. This V-8 engine aging method of dual converters produces an exhaust stream of equal flow and composition across both catalysts and overcomes the concerns of other comparative aging techniques.