Comparative Performance of Two Similar Vehicles with and without Catalyst under Actual European Driving Conditions

The Air Quality Agency (AQA) has appointed Union Technique de l'Automobile du Motocycle et du Cycle (UTAC) to conduct endurance tests in actual european traffic conditions on two vehicles, one with and the other without a three-way catalyst. The aim of these tests was to determine and compare evolution of emissions released by the two vehicles. Their emissions and consumption are measured at regular intervals on five types of cycles; performances are also measured. Tests are conducted at high speed and in abnormal or severe operating conditions (ignition failure, shortage of petrol, serie of decelerations, lambda probe disconnected) to determine the behaviour of a catalyst in high temperature environment.