diff --git a/code/m_chemistry.f90 b/code/m_chemistry.f90
index 26845cd..67024b2 100644
--- a/code/m_chemistry.f90
+++ b/code/m_chemistry.f90
@@ -14,6 +14,18 @@ real, private :: hrp_twostep
 contains
 
 subroutine init_chemistry
+
+    character(len=40) :: nrxn_string
+
+    if (nrxn == 1) then
+       reaction_type = "onestep"
+    else if (nrxn == 2) then
+       reaction_type = "twostep"
+    else
+       write(nrxn_string, *) nrxn
+       reaction_type = trim(nrxn_string) // "-step"
+    end if
+
     if ( reaction_type == "onestep" ) then
         lambda_onestep = pre * exp ( - beta / hrp )
     else if ( reaction_type == "twostep" ) then
@@ -22,6 +34,7 @@ subroutine init_chemistry
         beta1_twostep = beta1
         hrp_twostep = hrp
     else
+        WRITE(*,*) 'ERROR, UNDEFINED REACTION TYPE ', reaction_type
         stop
     end if
 
diff --git a/code/ysolve.f90 b/code/ysolve.f90
index 8ab3149..4bdb072 100644
--- a/code/ysolve.f90
+++ b/code/ysolve.f90
@@ -6,6 +6,7 @@
      IMPLICIT NONE
 
      REAL, DIMENSION(:), ALLOCATABLE :: u
+     REAL, DIMENSION(:), ALLOCATABLE :: inletbc
      REAL, DIMENSION(:,:), ALLOCATABLE :: y1,y2,yf,yold
      REAL, DIMENSION(:), ALLOCATABLE :: uxt,duxt
      REAL, DIMENSION(:), ALLOCATABLE :: dm
@@ -121,7 +122,7 @@
          pflame=0.
          DO i=1,nx
            pflame=pflame+y1(i,1)*hx
-           uxt(i)=y1(i,3)
+           uxt(i)= 1. - y1(i,1)
          ENDDO
 
          CALL dfnonp(nx,hx,uxt,duxt,1,1)
@@ -287,14 +288,17 @@
      END SUBROUTINE write_pre
 
      SUBROUTINE SET_BC
-      y1(1,1)=1.
-      y1(1,2)=0.
-      y1(1,3)=0.
+      INTEGER :: i
+
+      DO i = 1, nsp
+       y1(1,i) = inletbc(i)
+      END DO
      END SUBROUTINE SET_BC
 
      SUBROUTINE SET_IC
       INTEGER :: i, ifl, si
       REAL :: xi
+      REAL :: x(nx)
       REAL :: max_ysum
 
       ! initial flame thickness (0.2 pi n grids)
@@ -309,22 +313,37 @@
       ! initialize Yr field
       DO i=1,nx
        IF(i< nx-(si+ifl/2)) THEN
-        xi=0.+ctmp
+        x(i)=0.+ctmp
        ELSE IF(i> nx-(si-ifl/2)) THEN
-        xi=1.
+        x(i)=1.
        ELSE
-        xi=0.5+REAL(i-nx+si)/REAL(ifl)
+        x(i)=0.5+REAL(i-nx+si)/REAL(ifl)
        ENDIF
 
-!       y1(i,1,1)=(1.-xi)*1.
-       y1(i,1)=(1.-xi)   ! reactant mass fraction
+      END DO
 
-       y1(i,2) = (1./2.) * (lambda1/lambda2) * y1(i,1) * &
-         exp (-(beta1*(1. - xi))/(1. - hrp*(1. - xi)))
+      if ( reaction_type == "onestep" ) then
+        DO i=1,nx
+         xi = x(i)
 
-       y1(i,3) = xi
+         y1(i,1)=(1.-xi)   ! reactant mass fraction
+        ENDDO
+      else if ( reaction_type == "twostep" ) then
+        DO i=1,nx
+         xi = x(i)
+
+         y1(i,1)=(1.-xi)   ! reactant mass fraction
+
+         y1(i,2) = (1./2.) * (lambda1/lambda2) * y1(i,1) * &
+           exp (-(beta1*(1. - xi))/(1. - hrp*(1. - xi)))
+
+         y1(i,3) = xi
+        ENDDO
+      else
+          WRITE(*,*) 'ERROR, UNDEFINED REACTION TYPE ', reaction_type
+          stop
+      end if
 
-      ENDDO
 
       ! initialize species field
       ! max_ysum = maxval(y1(:,1) + y1(:,2))
@@ -350,14 +369,29 @@
        CALL init_chemistry
 
        ALLOCATE(   u(nx),STAT=ierr)    ; u=0.
-       ALLOCATE(  y1(nx,3),STAT=ierr)  ; y1=0.
-       ALLOCATE(  y2(nx,3),STAT=ierr)  ; y2=0.
-       ALLOCATE(  yf(nx,3),STAT=ierr)  ; yf=0.
-       ALLOCATE(yold(nx,3),STAT=ierr)  ; yold=0.
+       ALLOCATE(  inletbc(nsp),STAT=ierr)  ; inletbc=0.
+       ALLOCATE(  y1(nx,nsp),STAT=ierr)  ; y1=0.
+       ALLOCATE(  y2(nx,nsp),STAT=ierr)  ; y2=0.
+       ALLOCATE(  yf(nx,nsp),STAT=ierr)  ; yf=0.
+       ALLOCATE(yold(nx,nsp),STAT=ierr)  ; yold=0.
        ALLOCATE(uxt(nx),STAT=ierr)     ; uxt=0.
        ALLOCATE(duxt(nx),STAT=ierr)    ; duxt=0.
        ALLOCATE(dm(nx),STAT=ierr)      ; dm=diff
 
+       if ( reaction_type == "onestep" ) then
+         inletbc(1) = 1.
+       else if ( reaction_type == "twostep" ) then
+         inletbc(1) = 1.
+         inletbc(2) = 0.
+         inletbc(3) = 0.
+       else
+           WRITE(*,*) 'ERROR, UNDEFINED REACTION TYPE ', reaction_type
+           stop
+       end if
+
+
+
+
        CALL ludcmp(nx,100,100,1,0,0)
 
      END SUBROUTINE init_solver
@@ -365,6 +399,7 @@
      SUBROUTINE finalize_solver
 
        DEALLOCATE( u)
+       DEALLOCATE(inletbc)
        DEALLOCATE(y1)
        DEALLOCATE(y2)
        DEALLOCATE(yf)