In this paper, we analyze wave activity near Pluto. The situation is somewhat analogous to that near comets: molecules (in this case methane) escape from the atmosphere; some are phono-ionized, and a comet-like mass-loading of the solar wind plasma takes place. But the wave activity due to planetary ion interaction with the solar wind is quite different from that near comets. In the weak interplanetary magnetic field near Pluto, there is no MHD wave excitation; instead, we show that ion acoustic waves are excited. We construct a nonlinear theory of ion-acoustic wave excitation. These waves are excited due to a dissipative instability. The frequency, characteristic growth rate, and spatial scale of the instability are calculated. The main physical mechanism for wave amplitude saturation is the smearing of the velocity distribution function of the beam ions. We use a quasilinear approach to determine the characteristic scale for the electric wave amplitude.