He has done nothing that I suggested. Go back and read his posts, all he did was check to see if the intake was leaking and then complain that it has rough edges.
OP do this...
Leave the intake on the car and flash / go back to the stock map. Do not touch anything else. If the problem goes away its not the intake. If the problem is still there reinstall the tune with the stock intake. Do not drive the car hard but it should idle fine. If the problem goes away it is the intake or the install.
Is it possible to put the intake tube or the maf on backwards?
Not possible to install the tube or the maf backwards. There's only one slot of the maf and the maf will only fit in it one way, I thought that too for a minute but its all in there correctly.