Postflame injection of fuel has been proposed as a means of reducing chlorinated hydrocarbons (CHCs) in a combustion exhaust. In this study, the effects of this strategy on CHCs and NOx are investigated. A small amount of fuel, such as CO or CH3OH, has been injected into the postflame region from a turbulent combustion-driven flow reactor to assess its effect on the destruction of two CHCs (CH3Cl and C2H5Cl) and simultaneously, the oxidation of NO to NO2. The results suggest that this strategy is effective only in certain conditions. There is an optimal temperature similar to 1050 K,where NO is most effectively converted to NO2. Adding fuel to the postflame region increases the concentrations of both HO2 and OH radicals, but temperature is the key factor in determining which radical will dominate the reaction pathway. For the destruction of CHCs, attack by OH is the major destruction route, with T > 1200 K desired. For NO oxidation, the HO2 radical is the key species, and lower temperatures are necessary.