2001 Saturn SL1 • 166,616 miles

My saturn over revs in park to 2 rpm when put in drive rpms drop below 1 rpm but nearly 0. When in drive it boggs down when releasing breaks and applying gas. Also low water level light stays on till about 5 miles down the road and turns off
and the antifreeze container is full. One friend a mechanic stated could be fuel throttle sensor please any other possibilities.
November 1, 2012.

It sounds like you have several issues.
The thottle position sensor could be one of them.
I would reallly worry more about the coolant problem as that seems to indicate that you might have a head gasket leak or a leak in the coolant system. I would suggest getting the coolant system pressure tested and find out where, if any, fluid is getting lost first.
Then I would have the fuel pressure checked. You might have a bad fuel pump or bad fuel pressure regulator that is causing the problem at idle.
If the fuel pressure checks out okay, then you might need to replace the idle air control valve, IACV. It controls the idle under cold starts like a choke and also under load when you turn accessories on so the engine idle remains the same whether it is cold or at operating tmeperature or if there is a load on the engine from accessories at idle or not. You may need to replace the IACV.