Steering rack sensor, what does it do?

[mikecool84]

I was replacing my plugs on the weekend and noticed my steering rack sensor doesn't go anywhere.. because the plug's wires have been cut.

So the question is, what does the sensor do? and do I need to fix it?

Fyi. My steering is rubbish at the moment, very light when on centre. The rack and ball joints are tight, the centre steering shaft has a small amount of play from not loctiting the splines but nowhere near enough to account for the vague steering.

Thoughts?