Oxygen ions can be a major constituent of magnetospheric plasma, yet the role of oxygen in the magnetosphere is often not sufficiently understood. We examine the case of a thinning current sheet prior to the onset of magnetic reconnection. We perform 2.5D PIC simulations of a 3-species system of electrons, protons and heavy ions ($O^+$). We initiated the simulations using the well-known GEM Challenge configuration. Our approach differs from previous simulations involving heavy ions in two important aspects. First, we initiate the simulations with energized $O^+$ as opposed to using a thermal population. The energization is based on published in-situ measurements consisting of an initial dusk-ward velocity equivalent to $\sim$7 KeV. Second, we tracked the particles directly in the simulation rather than performing test particle tracing in post processing. We show three main results. First, energized dawn-dusk streaming ions exhibit sustained Speiser motion. Second, a single population of heavy ions can produce a stable bifurcated current sheet. Third, magnetic reconnection is not required to produce a bifurcated current sheet.