LR2 hesitation at light throttle

Hello, when you have a hesitation like that, it can be caused by many different things -- such as some kind of air leak or vacuum leak, an EGR system concern or other emissions controls issue or throttle control issue to name a few areas. The use of a diagnostic tool that can monitor data and the knowledge to interpret that data is important to get to the source of the problem. It's not going to be possible for anyone here to direct you to a single part -- you've certainly replaced a few "common" parts -- I'm concerned that you may not have needed the Mass Air Flow Sensor, and that it's money wasted. Testing is the best answer.