The present work concentrates on the two-dimensional steady incompressible flow of an Oldroyd-8 constant fluid between vertical plates influenced by a magnetic field. The cross diffusive and second-order chemical reactions are incorporated into the study. The homotopy analysis method (HAM) is used to obtain the series solutions of the transformed system of nonlinear equations. The effects of these parameters on the dimensionless velocity, temperature, concentration, skin friction, and Nusselt and Sherwood numbers are also investigated for various values of relevant parameters affecting the flow and heat transfer phenomena. The most relevant outcomes of the present study are that enhancement in magnetic field strength undermines the flow velocity, temperature, and concentration establishing thinner related boundary layer. Another important outcome is that an increase in the Dufour parameter upsurges the rate of heat transfer at the wall y = 0 while peters out at y = 1. Finally, the second-order chemical reaction parameter reduces the concentration distribution. The novel outcomes of this investigation will be helpful in the field of the aerosol technology.