Like clockwork, exactly seven days after I put my original ECU back in, the check engine light came back on, again reading fault 19. I really don't understand why it would take so long to come back on, especially since I probably put 1000 miles on the car in that seven days. Now that has reared its ugly head again, I know that it will continue to come back on within 30-60 minutes after I clear the code. Can anyone explain this strange behavior? I am still holding out some faint hope that the revised chip from the newer computer will help with this problem, but who knows with something as screwy as this. If anyone has any ideas, I am all ears.