Plastic materials’ applications are expanding on a daily basis due to their unique properties, which enable them to replace other materials in their appli- cations while still meeting customer needs thanks to advanced technology. In Sultanate of Oman 20.9% of the solid waste are plastics. As a result, more plas- tic produced, which leads to an increase in plastic waste. Since it is produced from an unsustainable crude oil source using a high-energy consuming method, plastic waste contributes significantly to soil, water, and even air pollution. As a result, they are non- biodegradable, resulting in high greenhouse gas emis- sions, a plastic waste crisis, and the non-renewable fossil fuel petroleum being depleted. One of the methods for handling plastic waste that has been devel- oped is the energy recovery process. Given that petroleum was the primary source of plastic, converting it to liquid oil via pyrolysis had enormous poten- tial, as the resulting oil had a calorific value comparable to commercial fuel. Pyrolysis of plastics is a chemical reaction in which larger molecules are bro- ken down into smaller molecules using heat. As a result, the aim of this study is to catalytically pyrolyze most commonly plastic waste (PET, HDPE) into a liquid oil using a spent FCC catalyst. This will contribute to the plastic waste management program while also providing a renewable energy source which can be used in boilers combustion and engines fueling, reducing plastic waste. Pyrolysis has been found to be an excellent solution for transforming Petro- plastics into different functional products, with liquid oil production reaching up to 80%, according to previous studies. This study conduct Pyrolysis of PET and HDPE plastic waste the poly fuel produced was analyzed by Gas Chro- matography (GC) instrument and compared with commercial diesel properties.