SSJSubgeta

Well Im about to replace my O2 sensor, its a 4 wire by the way. and the previous oem one i had is basicly crap and so are the plugs half broken and cant even clip together. Im all about plug and play, but i do know how to do wire work, solder, splice etc. So my quick question is, Do i really need these plugs or can i just wire them diretly to their own respective wire? coming from the ECU harness. I just wanted to double check and be on the safe side.