  The problem of competitive nucleation in the framework of Probabilistic
Cellular Automata is studied from the dynamical point of view. The dependence
of the metastability scenario on the self--interaction is discussed. An
intermediate metastable phase, made of two flip--flopping chessboard
configurations, shows up depending on the ratio between the magnetic field and
the self--interaction. A behavior similar to the one of the stochastic
Blume--Capel model with Glauber dynamics is found.
