diff --git a/code/m_parameters.f90 b/code/m_parameters.f90
index 6383699..5f17f29 100644
--- a/code/m_parameters.f90
+++ b/code/m_parameters.f90
@@ -33,6 +33,7 @@ module m_parameters
      ! Solver Control
      integer :: nsp, nrxn
      integer :: ncyc=0,int_pr
+     integer :: fctrl_species=1
      real :: absolute_tolerence=1e-8
      real :: dt,tf,t_now,t_uf,dt_uf
 
diff --git a/code/ysolve.f90 b/code/ysolve.f90
index 4bdb072..f066bcd 100644
--- a/code/ysolve.f90
+++ b/code/ysolve.f90
@@ -121,8 +121,8 @@
          pflold=pflame
          pflame=0.
          DO i=1,nx
-           pflame=pflame+y1(i,1)*hx
-           uxt(i)= 1. - y1(i,1)
+           pflame=pflame+y1(i,fctrl_species)*hx
+           uxt(i)= 1. - y1(i,fctrl_species)
          ENDDO
 
          CALL dfnonp(nx,hx,uxt,duxt,1,1)
@@ -355,7 +355,7 @@
       ! calculate flame position
       pflame=0.
       DO i=1,nx
-       pflame=pflame+y1(i,1)*hx
+       pflame=pflame+y1(i,fctrl_species)*hx
       ENDDO
 
      END SUBROUTINE SET_IC