Proton Exchange Membrane Fuel Cells (PEMFCs) with three distinct flow field designs were investigated: sinusoidal with a diffuser at the intake, sinusoidal serpentine, and serpentine flow fields. The sinusoidal flow field with a diffuser at the intake has been found to be the best flow field design. Following that, parametric experiments were performed on PEMFCs equipped with a sinusoidal flow field with a diffuser at the intake. Operating pressures (1–3 bar), back pressures (0–3 bar), anode humidification temperatures (40 °C–80 °C), cathode humidification temperatures (40 °C–70 °C), anode flow rates (250 sccm to 350 sccm) and cathode flow rates (250 sccm to 400 sccm) and cell operating temperatures (COT) ranging from 40 °C to 70 °C were all adjusted. The experimental findings showed that a COT of 60 °C, a 3-bar back pressure, a 3-bar working pressure, cathode humidification at 70 °C, anode humidification at 60 °C, and flow rates of 300 sccm for the anode and 350 sccm for the cathode resulted in the best PEMFC performance.