This work aims study on the method of NOx reduction and performance enhancement by analysis of MPFI multi-cylinder gasoline engine running on LPG using the gas injection system and vaporized water-methanol induction to the intake manifold. For the generation of vaporized water-methanol, heat from the exhaust gas has been used. Different percentages of water- methanol by mass basis were used with variable engine speed ranging from 2000 to 4500 RPM. The outcomes indicated that as the percentage water-methanol induction level of the engine increased, there is a slight increase in percentage of useful work, while the NOx decreased drastically about 47%. Additionally, the engine brake thermal efficiency gains. The mean gain in the brake thermal efficiency for a 20% water methanol with LPG is approximately 1.5% over the use of LPG without water-methanol induction.