i put the knock sensor in my car and got a plug and it has to wires one of the wires i put it to my ecu and i dont kno what to do with the other wire but i still have a check engine light does any one no what i did wrong

 

The knock sensor should only have one wire. What knock sensor did you use?

 

I think some of the older knocks have 2 wires....and the extra is a ground if Im not mistaken.