The large-scale behavior of FHP-type cellular automata is investigated in the presence of some additional random effects. It is shown that every translation-invariant stationary state of the modified model is a superposition of product measures. By means of the entropy argument of Yau and of Olla, Varadhan, and Yau, the macroscopic (Euler-type) equations governing the hydrodynamic behavior of FHP automata are also derived.