MAD 4Runner

I am in the process of replacing the head gaskets in my 4Runner and I have heard a lot of stuff about this knock sensor. I would prefer not to have to buy another once since $150 just doesn't fit in my budget right this moment. What do I need to do to make sure that I can still use the one I have? Also some one told me I need to replace the knock sensor wire. Where can I get that, I have only been able to find the sensor on line.

Has anyone had success with not replacing either?? What did you do to make sure that you could reuse them?

Thanks in advance for everyone's help!!!

snap-on

i replaced just the wire... left the sensor .... got the wire from the dealer... $15 or something like that