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

Answer

I decided to answer my own question because it miught help someone out there with a similiar 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.

First answer by Rebel renegade one. Last edit by Rebel renegade one. Contributor trust: 52 [recommend contributor]. Question popularity: 10 [recommend question]