For a reaction, if Kp >Kc , the forward reaction is favoured by low pressure.
Kp =Kc (RT)Δn
Since Kp >Kc
∴Δn>0, i.e. the product side contains more particles than the reactant side.
At low pressure, the equilibrium will shift in the forward direction so that more and more gaseous products are formed. This will increase the total pressure and nullify the effect of low pressure.