Common Rail Direct Engine (CRDI) engines are used for transportation and other sectors due to their high fuel conversion efficiencies. Waste plastic pyrolysis oil can be a substitute to the depleting petroleum reserves. Plastic oils are durable and takes longer time to degrade because of stronger molecular bonds and it repel to natural processes of degradation. This investigation deals with the effect of increasing the fuel blend ratio and with increasing the fuel injection pressures on single cylinder, CRDI diesel engine using plastic oil and diesel blend. The fuel blend varies from 5:95%, 10:90% and 15:85% (Plastic pyrolysis oil and diesel) respectively with various fuel injection pressures of 400 bar, 500 bar and 600 bar. The emission, performance and combustion characteristics were evaluated and analyzed in this work. Plastic oil blends were able to operate in diesel engines without any engine modifications. The results shows the brake thermal efficiency increases with the increasing fuel injection pressure. The engine with the fuel injection pressure of 600 bar gives better brake thermal efficiency at the full load condition for the 15PDB fuel blend. Hence it was concluded that the increasing the pressure, increases the performance and decreases the emissions.