Abstract: Awareness regarding atmospheric pollution effects on the environment and the health of humans, plants, animals and other living organisms and flora and fauna World over has inspired many researchers. Extensive research was carried out all over the world with particular reference to Industrial & Vehicular pollution. Automotive catalysts designed to detoxify the exhaust were implemented in USA in the vehicles of the model year 1975. By 2014 about 40 years have been spent all over the world in the research of automotive catalytic converters. The published papers can be categorized into five groups mainly based on (i) Numerical models (ii) Computational Fluid Dynamic models (iii) Design of Catalytic converters per se (iv) Laboratory experimentation (v) Development of catalytic materials. This paper aims at reviewing how the present day catalytic converter used in automobiles has evolved in the last four decades. About 150 technical papers published in various journals were studied. Some 52 papers are described briefly which indicated the furtherance in the said research. Important conclusions drawn from a few papers are discussed in the end. An exhaustive list of 151 references on the subject is appended.