Despite being known by its ability in the production of nearly full dense sintered parts, Metal Injection Molding (MIM) allows also tailoring porous microstructures for special applications such as small-size flow restrictors. In other words, through simple modifications in the sintering parameters, an interconnected porous microstructure with the capability of control the gas flow rate from a high to low pressure region can be obtained. In this work, the effect of sintering temperature and time is addressed over two parameters: i- the microstructure evolution of the stainless steel parts and ii- the gas flow behavior in each component under different upstream pressures. Therefore, the parts were characterized in terms of porosity and shape factor by image analysis while a nitrogen flow test apparatus was used to elucidate the gas flow conditions. The results show that production of tailor-made flow restrictors is feasible by MIM.