O K-shell photoionization of the CO₂ molecule causes antisymmetric vibrations v₃′ in the core-ionized molecule. The v₃′-resolved partial cross sections and asymmetry parameters are measured in the Σ_u shape resonance region above the O K-shell ionization threshold of the CO₂ molecule. Neither the shape resonance energy in nor the value of shows v₃′-dependence. This v₃′-independent nature is attributed to the fact that v ₃′ vibrations do not cause any change of the size of the potential box responsible for the formation of the shape resonance. Multiple scattering calculations employing the v₃′-dependent fixed-nuclei approximation reproduce well the measured v₃′- resolved partial cross sections.