1996 Ford Probe

Engine Mechanical problem
1996 Ford Probe 4 cyl Front Wheel Drive Automatic 78000 miles

I have taken my Probe SE to Auto Zone to have my engine light checked and diagnosed. It turned out that I have a problem with an Idle Speed Control which shows on the diagnostic tool's screen.
I would like to know, if I may, what cost am I looking on if I decided to repair it and what is severity of this damage to the car. In other words, how long can I go without fixing it?
Thank You for Your time and an effort.
Katherine from Oregon City
August 23, 2010.

Try cleaning out the idle air control valve and see what happens-Dunno know how long but when it quits for good it won't idle or idle so high, unpredictable

Aug 23, 2010.