Hybrid ARQ (HARQ) has been identified as one of the most common optimal error control protocols. However, due to the complexity of the existing error codes, the use of HARQ in WSN can be viewed as energy-consuming, if it were not implemented properly. Multi coding as an extension to the HARQ protocol can be a promising method for improving a network plagued by high error rates. However, in implementing the error correcting codes for the better error rates, one may increase the overhead in terms of computational redundancies added to the transmitted bits, especially in a highly condensed network. This can lead to further degradation of the remaining energy and fluctuations in the Bit Error Rates (BER). Based on a previous study, other aspects must be considered to indicate the congestions present, rather than solely be dependent on the Signal to Noise Ratio (SNR). This paper proposes a congestion control based on the node density variation to control the congestion caused by different levels of numbers of nodes deployed, as well as the complexity of error correcting codes which were used in the network. We collected the BER values, as well as the remaining energy and latency, to study the optimal error correcting codes which varied with the codeword length, and the respective error correcting capabilities which suited the defined congested environments. Based on our results, our proposed multi coding assignment can adapt to the sudden changes in the channel condition, as well as improve the performance in terms of optimising the error rates, and the remaining energy across different types of channel conditions.