Gas oil components, coking process recycle, and heavier hydrocarbons are cracked or coked in the coking vessel by injecting an additive into the vapors of traditional coking processes in the coking vessel. The additive contains catalyst(s), seeding agent(s), excess reactant(s), quenching agent(s), carrier(s), or any combination thereof to modify reaction kinetics to preferentially crack or coke these components. Modifications of the catalysts in the additive improve performance for certain desired outcomes. One exemplary embodiment of the present invention uses the olefin production capabilities from newly developed catalysts to increase the production of light olefins (e.g. ethylene, propylenes, butylenes, pentenes) for alkylation process unit feed, the production of oxygenates, and petrochemical feedstocks, such as plastics manufacture. Another exemplary embodiment of the present invention is the use of the olefin production from newly developed catalysts to improve the coker naphtha quality. A third exemplary embodiment of the present invention uses the cracking characteristics of newly developed catalysts to optimize the production of light gas oils, naphtha, and gases from the coking process.