Too much carried the wrong way (2,4)
I believe the answer is:
de trop
'too much' is the definition.
(I've seen this in another clue)
'carried the wrong way' is the wordplay.
'carried' becomes 'ported' (porting is a kind of carrying).
'the wrong way' shows that the letters should be reversed in order.
'ported' in reverse letter order is 'DE TROP'.
(Other definitions for de trop that I've seen before include "Unwanted - excessive (French)" , "Unnecessary" , "not to drink too much" , "surplus to requirements" , "Superfluous (French)" .)