what would cause these problems to happen on 1996 Lexus LS400

traction light came suddenly stays on car runs rough
car when stopped wants to stall.also engine light came on

Asked by for the 1996 Lexus LS400
engine light: catalytic converter.
wanting to stall: the transmission is about to die, and thats also y the traction control is freaking out and why its a rough ride.