When I am stopped with foot off the gas and on the brake, and the car is warmed up, the idle will drop to 5-600rpm and the oil light and alarm will come on. If I touch the gas and rev to 800-1000rpm, it all goes away. Do I need a new Idle Control Sensor and where is that located?
A SYMPTOM of a problem is not enough information to decide what part to change.
Each part of the system which controls idle speed needs to be checked.
Part one is the part which tells the engine computer what the engine speed is.
Part two is the command sent by the engine computer (if any) to control engine speed.
Part three is the reaction of the part (or, system) which the engine computer sends commands to.
Check/test each part of the system for idle speed control.
So, you have: 1. detection, 2. decision/command, 3. reaction to command.
Stop at the local Autozone and have them see if any fault codes are stored in the computer. If there are, post them here.