Sensor above the oil filter-what is it?

[johny1]

Regarding '85 4runner:
There is something looking like a sensor screwed directly above the oil filter into the engine, it looks like a big bolt with a plastic removable round clip at the end and a wire coming out of it. Does anyone know what this is? It had come off loose from the plastic round clip but it did not affect performance at all? Thanks

 

[fourwd1]

Sounds like the oil pressure gauge sending unit.

 

[johny1]

I looked at a picture of an oil pressure sender for my truck and it looks different then the one I see about 3-4 inches above the oil filter.
Thanks

 

[fourwd1]

You have an 85, that means EFI. I think that's the knock sensor.