Membrane computing is a (biologically motivated) theoretical framework of distributed parallel computing. If symbol-objects are considered, then membrane systems (also called P systems) are distributed multiset processing systems. In evolutioncommunication (EC) P systems the computation is carried out with the use of noncooperative rewriting rules and with (usually the minimally cooperative) transport rules. The goal of this article is to improve the existing results on evolution-communication P systems. It is known that EC P systems with 2 membranes are universal, and so are time-free EC P systems with targets with 3 membranes. We prove that any recursively enumerable set of vectors of nonnegative integers can be generated by time-free EC P systems (without targets) with 2 membranes, thus improving both results.