A circularly polarized, large-amplitude Alfvén wave in a plasma with finite plasma ß becomes parametrically unstable under specific plasma conditions, in which the pump wave will decay into several daughter waves with different wavenumbers and frequencies. Magnetohydrodynamic simulations have been conducted to investigate the evolution of the parametric decay process, using the MRCv3 code. This code is based on the computational library libMRC, which provides a number of numerical methods that solve MHD and extended-MHD models. For the MRCv3 simulations, a uniform Cartesian grid with periodic boundary conditions is used, with the assumptions of no background flow and a uniform background plasma density ρ and magnetic field B0. Results from these simulations will be presented, discussed, and compared to previous numerical and analytic results.