The sensor on the power steering system is used to control idle speed while the vehicle is not moving, and the steering wheel is being turned. So it could likely be the problem. If it has a sensor it will be on the power steering pressure line. But there is not one listed for your vehicle.
The next thing I would be looking at is the belt tension. If the belt is not the problem, we would go on to inspect the ISC valve (Idle Speed Control).
Ste pressure switch is only for idling up the engine so it creates the extra power necessary to turn the pump while the vehicle is sitting still. IT sends a signal to the computer saying, there is pressure on the power steering system, and the computer idles the engine up, similar to when you turn on the air conditioning while the engine is idling.
So to answer that particular question..
"will it make the steering tight at idle and fine going down the road "
No, it does not have anything to do with it. The idle air control vlave will have to be inspected if the problem is while the vehicle is moving.
Is the engine idling funny? What's it doing high... low idle??
I misunder stood your second version of the question. Don't pay attention the entire last reply I left you...Sorry for any confusion it might have given you...
If there is a sensor in the pressure line...
Then it would definately be the problem, either that or belt tension, like I mentioned before. That is what it controls, this exact problem...
But, does the power steering work fine while driving slowly? If not, then you have hydraulic system problems, still.
I take it doesn't wine at you when you turn the wheels, right? That would indicate a possible air pocket in the system, if it did. The fluid would be frothy looking or pink if this was the case.
My information (ALLDATA), doesn't show the pressure switch. If it has one, it would be on the high pressure line for the power steering system. It doesn't even have a labor time for changing it, so...
If you don't see the pressure switch then you have a, brand new, bad, power steering pump.