  A partial wave analysis (PWA) of the $\pi^- \pi^- \pi^+$ and $\pi^- \pi^0
\pi^0$ systems produced in the reaction $\pi^- p \to (3\pi)^-p$ at 18 GeV/$c$
was carried out using an \emph{isobar} model assumption. This analysis is based
on 3.0M $\pi^- \pi^0 \pi^0$ events and 2.6M $\pi^- \pi^-\pi^+$ events and shows
production of the $a_1(1260)$, $a_2(1320)$, $\pi_2(1670)$ and $a_4(2040)$
resonances. Results of detailed studies of the stability of partial wave fits
are presented. An earlier analysis of 250K $\pi^- \pi^- \pi^+$ events from the
same experiment showed possible evidence for a $J^{PC}=1^{-+}$ exotic meson
with a mass of $\sim$1.6 GeV/$c^2$ decaying into $\rho \pi$. In this analysis
of a higher statistics sample of the $(3\pi)^-$ system in two charged modes we
find no evidence of an exotic meson.
