1995 chrysler cirrus stalls intermittently.

If anyone can provide a little assistance..... much appreciated.

I have a 1995 chrysler cirrus. My cpu died and I had it replaced along
with the MAP sensor.
After the computer was fixed my car started to stall. It usually
stalls on startup (around 20 - 30 seconds after firing up). I then
turn it back on, and it seems to run fine. This happens when leaving
for work and coming home from work. I took it back to my mechanic who
replaced the MAP sensor again, and this did not fix the problem. I get
the error codes 11, 13, 55. Ocassionally the car will stall when
coming to a stop. I then have to quickly put the car in neutral and it
runs fine. I am not mechanically inclined but do have friends who can
help, but anyone who has experienced a similar problem and has any
hints would be much appreciated. I keep regular maintenace on the
vehicle and with the exception of this particular incident it has been
a good vehicle.

Thanks....