It is shown that the direction of the photoelectron recoil momentum transferred to the photoion influences molecular photoionization dynamics, resulting in the appearance of a specific mode–channel interdependence. We disclose the interdependence and the interplay of the core-hole- and photoelectron-induced recoil effects by passing to normal mass-dependent modes in both coordinate and momentum spaces. As an example, the vibrational structure of the 1s−1 photoelectron line of CO2 is investigated in detail. The intensity of bending and symmetric and asymmetric stretching vibrational and rotational excitations is found to differ substantially in the Σ→Σ and Σ→Π photoionization channels.