Mitsubishi Repair: mitsubishi nimbus, air fuel ratio, auto electrician

Question
hi i was reading your answer for Linda's 2000 nimbus and i have a similar problem with my 1999 nimbus only i took it to an auto electrician and they said there was a knock in my motor i need a knew one so I've just spent $5070 on my motor and the engine light still comes on and stalls on me,its ok when the engine is cold but when it warms i get a little shudder like its dropped in gear and then the light comes on sometimes I'm lucky to get were i need to be other times i stop and quickly have to pull over before i cant,sometimes it will start straight away other times i have to wait 10 - 20 minutes before it will start again,don't get me wrong it starts everytime its when I'm about to put it back in gear it stalls again do you think it might be my computer as well please let me know I'm getting scared to drive my car thanks,Fiona.

Answer
Fiona,
Sorry for the late reply.  You should have the computer checked out.  Once the engine reaches normal operation temperature, the computer starts taking over to regulate ignition timing, air/fuel ratio mixture, and other sensors to control proper engine operation.  So if the computer is malfunctioning, you can experience the type of problems you described.  
Good luck!