Have Issue - Not sure what it is

[X5Dawg]

I am not sure if I am going to be able to explain this properly, but for the past 4-5 months my X has been running a little funny. Cranks fine, acceleration is fine, however it seems every so often to like "cough" or hesitate. Mainly notice it after accelerating and then letting off the gas pedal - then it happens. Almost feels like it is having trouble breathing. I thought it might have been related to my catalytic converters, but I just had those replaced last week and the issue is still there. In the past year I have replaced the plugs, O2 sensors, water pump and tstat, and the air filter is clean.

Anyone else experience this or might know what the issue is??