This study looks at the application of a titanium dioxide (TiO2) catalytic nanoparticle suspension to the surface of the combustion chamber as a coating, as well as the addition of hydrogen gas to a four-stroke spark-ignited carbureted engine as a possible technique for lowering engine-out emissions. The experiments were conducted on two identical Generac gasoline powered generators using two, four and six halogen work lamps to load the engine. One generator was used as a control and the second had key components of the combustion chamber coated with the catalytic suspension. In addition to the coating, both engines were fed a hydrogen and oxygen gas mixture and tested at low, medium and high loads.Using an unmodified engine as a control set, the following three conditions were tested and compared: addition of hydrogen only, addition of coating only, and addition of hydrogen to the coated engine. Operating the engines on standard gasoline in a laboratory, emission gases were transferred via a heated line to be analyzed by an FTIR. Overall, the experimental results showed that at medium load the TiO2 coating provided up to a 18% reduction of hydrocarbons (HC) and up to 20% reduction of oxides of nitrogen (NOX) depending on the respective load. At the highest load, the addition of hydrogen to the TiO2 coated engine resulted in comparable carbon monoxide emissions relative to the control engine while also providing a reduction of 5-20% of both NOX and HC.