What will cause a high pitched grinding-whining at Idle and in all gears only when the accelerator is depressed?

I decided to answer my own question because it miught help someone out there with a similar problem. The Squealing or grinding sound wasn't that at all. I believe the sound was coming from the Catalytic Converter. The sound traveled up the Exhaust pipe to the Digital EGR valve where the sound was heard. If a Catalytic converter problem is suspected it can cause a Digital EGR valve to go bad by blowing a Gasket. Much like I did when trying to fix this problem. The part digital EGR valve is about 168.00 dollars to replace. You can get it in a Car Boneyard for much much cheaper. When replacing the gaskets on a Digital EGR valve you might have to go to a Store where they will have special Gaskets and parts because the Gasket in between the EGR Solenoid and the Valve body is a Aluminum Gasket with a cork or carboard type of surface to it.

If you suspect a Bad cat and want a quick way to test your car, Go to the tailpipe and place your hand down near the exhaust. If you do not feel any exhaust fumes whatsoever, there is a good possibility of a restricted exhaust system. The Catalytic Converter for a 1989 Pontiac Bonney LE is about 140.00 dollars for the cheapest one. Try and get your parts on E-bay if you can. I bought a Cat for 55.57. i hope this helps someone else with there problems.

Oh and by the way, The problems I was experiencing made it seem like I had a Torque converter problem or a tranny problem. If the Digital EGR valve is bad will cause Poor Idle. Poor Performance. Poor Driveability.