  Analysis on very detailed measurements of resistivity ($ \rho $) and
thermoelectric power (S) of magnetic impurity (Co) substituted iron silicide
(FeSi) has been presented in this report. The impurity valence electrons of Co
dominate the whole physical properties at low temperatures below 35 K, below
the critical concentration x$_{c}$. The negative thermopower and the positive
slope in the resistivity at low temperatures are exotic and show that the
system is not entirely insulator below the critical concentration of MIT
(x$_{c}$). So, due to the external impurity electrons, the system's magnetic
ground state could change considerably compared to the parent compound FeSi.
This report may help unveil the exotic nature of the ground state in the
semi-metallic regime between x = 0 to x = 0.02. We have also explained the
electrical and thermal transport properties using the two-band model.
