Hey Scotty, have a 1994 Toyota Camry that bogs under load. I have checked fuel pump, TPS, fuel pressure regulator, CAT and O2 sensors all work fine. Seems like there is low fuel pressure in the rail. Can the pulsation damper cause a restriction to the rail and the injectors?

yes, it can, as can a clogged fuel filter or weak pump. Change the filter then pressure AND volume test the pump. Dirty injectors often do that too, try this https://www.youtube.com/watch?v=bKGI9N_yWd0