I have an 02' dodge van with 5.9 engine that sputters and stalls when put in reverse on initial start up. drive works fine. drive it a little ways reverse works fine. Idle in neutral dose not help. Problem started after I changed o2 sensor in front of catalytic converter. I have changed IDAC motor and cleaned throttle body. Any ideas or help would be greatly appreciated. Thanks

Does it still do it if you give it a slight bit of gas before shifting into neutral?

yes. if it was carburetor motor i would say it acts like accelerator pump