Stalls when put into gear

Did it just start doing that after the parts were replaced or was it doing it prior to the repairs and they were done to correct the problem? If you step on the gas as you put it into gear does it still stall? Does it idle okay or do you need to give it throttle?

If it was running okay and replacing the parts caused this the first thing I would do is to clean the throttle body bore and the idle air control passages. Next would be that that the battery was disconnected so the PCM needs to re-learn the idle speed. Cleaning the bore and idle passages would make that occur faster.