mcarrico2

I have a 89 toyota truck 4x4. I just had the engine rebuilt and eitther the engine shop lost the knock sensor or when I bought the truck it did no thave one. I really do not want to buy a new one for 170 bucks....I also do not know what the part number would be for it. I see a few used ones on ebay however no part number. The clips look different also. Any help would be appreciated.