A secure routing mechanism is the basis of security in mobile ad hoc networks. Seeing that nodes have to share routing information in order to find the route to the destination, further an ad hoc network is an open setting where everyone can participate, trust is a key concept in secure routing mechanisms. In this paper, we propose a novel opinion based trust evaluation model to detect misbehaving nodes and further securing data transmission by avoiding such node from path selected. Misbehaving nodes are detected based on the node own direct observation, but in the circumstances of network failure as node congestion or collusion a well-behaving node can be misidentified. Therefore we require opinion of other nodes before proceeding to isolation of such misbehaving node. Source nodes maintain a path reliability index associated with each path to the intended destination. The most trustworthy and reliable path is selected by source node for forwarding data packets to the intended destination. We have evaluated the misbehaving node detection rate and the performance of our method along a number of parameters through simulation. Results show that our method increases the throughput of the network while also discovering a secure route.