Thermoelectric generation is one of the most promising technologies for waste heat recovery from the exhaust gas of an automobile engine. An automotive exhaust gas-based thermoelectric generator (TEG) utilizes the waste heat from engine exhaust and provides improved fuel economy. Several factors, including the heat extraction ability from the exhaust gases and the temperature distribution on the hot side of the heat exchanger affect the thermal performance of the TEG. A proper design of exhaust heat exchanger helps achieve more efficient utilization of thermal energy for the uniform temperature distribution. The efficient performance of exhaust heat exchangers depends on various parameters, including heat exchanger material, type of heat exchanger, and fin configuration. The present work investigates the feasibility of using different pin fin configurations as a heat transfer enhancer to improve the thermal performance of the exhaust heat exchanger. A three-dimensional computational fluid dynamic (CFD) model is developed to simulate the thermal performance of an exhaust heat exchanger with different configurations of circular pin fins, namely smooth channel, inline, staggered, circular progressive, and circular regressive. The thermal performance of the exhaust heat exchanger is numerically investigated at different temperatures to compare the heat transfer and pressure drop evaluation. In the present study, an effective heat exchanger design is proposed to utilize as much heat as possible from the exhaust gas of the automobile engine at the cost of an acceptable pressure drop.