Stalling

You need to include a lot more detail than that. When does the stalling occur? Just when approaching a stop? While you are driving at a steady speed? What does it take to restart the engine? Was the battery recently disconnected or run flat? Are you aware that disconnecting the engine computer will cause a low idle speed that results in stalling and hard starting? Have you read the diagnostic fault codes? Those would have been erased when the engine computer was replaced, so any codes now would have been set after that. When you have an engine running problem, please list which engine you have.