In fact, there were a LOT of sneaky refs to Equalizer throughout the series:

Peter spraying lighter fluid on the limo driver and threatening to light him up in Rose Garden was a direct steal from Eq ep Time Present, Time Past; also the use of Caldrin as a sleazy contact, was played by the same actor who played that role (they had different first names) in Eqz.

Even "Pop" was first used on Eqz with a dire threat to "NOT call me that!" I