The research studied the performance of liquid products obtained in catalytic pyrolysis from high density polyethylene (HDPE) residues using the equilibrium catalyst (E-Cat) as catalyst without prior treatment. The effect of operating temperature on the performance of liquid products was studied, and the results of catalytic pyrolysis with untreated E-Cat and catalytic pyrolysis with treated E-Cat were also compared. For the investigation, samples of HDPE residues from urban solid waste (RSU) were used, also E-Cat from the Fluidized Catalytic Cracking Unit (FCC) of a local refinery was used, a laboratory scale system for catalytic pyrolysis was used. The highest yield of liquid products in catalytic pyrolysis was 89% and 80% using treated and untreated E-Cat respectively, the operating conditions that maximize the performance of liquid products in catalytic pyrolysis were a temperature of 873.15 K with the ratio E-Cat/HDPE of 10%, at higher temperatures the yields decrease in both cases. E-Cat treatment improves the performance of liquid products obtained from catalytic pyrolysis compared to the results obtained from untreated E-Cat.