Abstract: This paper examines the “impact of Downstream Oil Deregulation Nexus Petroleum GDP and the causal relationship between downstream deregulation. Petroleum GDP.ARDL technique was used in analyzing the regression estimates. Based on the findings, the study found a Two-way causation to have existed between PPMS and petroleum GDP and between PPMS and PMSP. The regression estimate has indicated a positive significant impact between PMSP and economic growth (proxy petroleum GDP).