First off the car is an 05 impalla with the 3.4, 70k miles, 100% stock. The issue I am having is my car is making an awful noise under hard acceleration and I don’t know what is causing it. It’s a screeching/whistling type sound,sort of has a metallic ring to it and it only happens when accelerating and the motor is under a decent load. When it makes the noise, if you let off the gas it will go away, and if you continue to accelerate hard the noise gets real faint and seems to disappear but it is hard to tell. If you’re easy on the gas it won’t make the noise, and other than that the car is driving completely normal. My buddy and I have pinpointed the noise as coming from underneath the car somewhere behind the front seats, so I am thinking it is an exhaust problem.
So any tips or suggestions on what I should be looking for? This is the first real issue the car has had and I am just hoping that this isn’t an issue with my cat 