Wireless communication has proved a advantage to the communication industry but it has also produced many challenges to the researchers. Mobile Ad hoc Network MANET)  is one such area which has undergone tremendous research. MANET is a self-organizing network of mobile nodes forming a temporary network. Energy conservation is a challenge in MANET. This paper describes a customized DSR approach called IDSR. The residual energy of neighbour node is compared with the average energy of the path and accordingly the node is disabled. This proposed algorithm showed positive results in terms of energy preservation when simulated using 50 nodes UDP traffic. Energy consumption in IDSR reduces to 49 % as consumed by DSR. There are still various scopes for researchers to optimize DSR. MANET has many salient features which make it different from other networks and enforce many constraints on it. These features include lack of infrastructure, dynamic topology, bandwidth, power constriction etc. The most challenging task in such a dynamic network is routing. Many routing protocols have been proposed and optimized till date and constantly undergoing further evolution. The proposed approach can show interesting results in different scenario. In different application scenario, different approaches can be exploited.