Recent results from extending the project at the Excited Baryon Analysis Center (EBAC) of Jefferson Lab to investigate final state interaction in 3-pions decay of meson resonances will be reported. We employ a dynamical coupled-channels formulation which has been used to extract N* information. The formulation satisfies the 3-pions unitarity condition which has been missed in the existing works with the isobar models. I report the effect of the 3-pions unitarity on the meson resonance pole positions and Dalitz plot.