© 2021, King Abdulaziz City for Science and Technology.In this study, the effect of the catalytic converter (cc) coated with Al2O3/SiO2/TiO2 catalyst on the exhaust emissions of CO, NOX and HC was measured at 0, 25, 50, 75 and 100% load conditions from the diesel engine. Al2O3/SiO2-coated TiO2 powders were prepared by wet impregnation method and then coated to 32 pieces of 11 × 11 cm aluminium wire mesh plate by calcination method. The synthesised catalyst characterization was performed by XRD, EDX, SEM analyses and UV spectrophotometer. The exhaust emissions of CO, HC and NOX from the diesel engine were measured by GA-4040 gas analyser with and without a catalytic convertor. The emission results were evaluated for statistical analysis by IBM SPSS 22 Statistic Data Editor. Hence, it was seen that the modified catalytic convertor represented 43.05% reduction of NOX emission as a maximum at 75% load. Moreover, 56.84% decrease was seen in HC emissions as a maximum at 25% load. Furthermore, CO emissions reduction was measured to be 66.7% as maximum at 25% load. Consequently, the results of this experimental study showed that the catalytic converter coated with Al2O3/SiO2/TiO2 catalyst greatly reduced the exhaust emissions from the diesel engine and the synthesised catalyst can be alternative to overwhelm air pollution problem emitted from transportation.