This study presents a comprehensive Computational Fluid Dynamics (CFD) analysis of internal flow behavior within an engine exhaust manifold under various operating conditions. The primary focus is on examining velocity and pressure distributions across different scenarios. The simulations explore the effects of varying inlet mass flow rates (0.004 m³/s, 0.006 m³/s, and 0.008 m³/s) using three turbulence models: k-ε, k-ω, and k-ω SST. The analysis provides detailed insights into complex flow patterns, including meshing strategies, boundary condition setups, and solver configurations, with particular attention to phenomena such as flow separation, recirculation, and turbulence. Parametric variations are thoroughly examined to assess how different turbulence models and mass flow rates influence critical parameters like pressure and velocity. The findings offer valuable insights into the manifold's flow dynamics, contributing to design enhancements to improve engine performance and reduce emissions.