Fuel obtained from waste plastic has been used in this study due to the lavish consumption, and non-stop price hiking made the researchers focus on finding a suitable substitute for conventional fuel. The plastics were non-biodegradable, and also its continuous usage in our daily life together created awareness about waste plastic management among us. With this, plastic oil could be a promising alternative fuel and also solves the issue of seating waste plastics in landfills. Even though plastic oil has a closer calorific value and viscosity to diesel, its volatility is less than diesel. In order to improve its volatility, a titanium dioxide oxide nanoparticle of 50 ppm, 100 ppm, and 150 ppm was doped. A single-cylinder diesel engine's performance, emission, and combustion phenomena were tested with nano blended waste plastic oil at three different fuel injection pressure of 210, 230 and 250 bar, respectively and the results were analyzed. An improvement in engine characteristics was recorded for nanoparticle blended fuels. High nozzle opening pressure improves the spray penetration inside the engine cylinder, promoting the combustion quality. The study concluded that blending 150 ppm Titanium-dioxide with waste plastic oil would be a suitable alternative for diesel engines operating at 230 bar of injection pressure.