The need for energy resources that do not belong to the group of fossil fuels and a wide availability of various low-calorific gases leads humanity to search for solutions to adapt external sources of force that would allow for the use of these resources. One of such solutions is the usage of non-thermal plasma applications for pre-ignition stage, ignition, and, finally, combustion. Plasma assistance is a promising technology for improving processes of ignition and flame stabilization, as well as propagating flame speed. This study focuses on influence of the non-thermal plasma on both for CH4, CO2 gases, and their mixture in pre-ignition stage by performing emission spectroscopy, and determining tendency of excited species at different frequency rates for optimal plasma parameters to reduce NO formation and increase efficiency during combustion. The results obtained exhibit a non-linear dependence of radical’s emission from the frequency of plasma. As an example of possible profits from correctly choosing plasma parameters, the calorific value of gases increased from 2.86 times for BG25/75 to 4.78 times for BG30/70. However, the decomposition on higher frequencies causes higher rates of nitrogen-bands emissions, which would increase NOx emissions in the combustion process.