Mobile Ad Hoc Network is the wireless network with no centralized monitoring system. The nodes are free to move anywhere in the network. These mobile nodes also act as routers and make the routes for any data transmission on their own. They take the responsibility of route discovery and packet transmission of other. This cooperative approach of packet transmission has made these ad hoc networks much popular. Due to lack of infrastructure and centralized monitoring system, these networks are vulnerable to the security threat. If there is an intruder among the mobile nodes, the whole system can be damaged to the large extent. Since there is no central framework to monitor the security issues, mobile nodes have to implement their own security feature. The security feature, that is to be implemented on the network, must pass through simulation so that the actual effect of it on the performance of network may be analyzed prior to its implementation. This paper focuses on the effects of adding MAC layer security feature to the mobile ad hoc networks. Also the effect of adding power saving mode, which dominates the co-operative behavior of mobile nodes, has been discussed. This analysis gives a better picture for the implementation of routing protocols.