Just had a few modifications to my 97 SS Camaro. 1)Installed new Stainless works 3" lt headers and exhaust, 2) New 3.73:1 rear end, 3) New water pump and sensors. Now I have this new noise, it happens from about 15 mph to 50 mph and only in 2,3 and 4th gear. The noise is very similar to when you leave your window down just a crack, but both windows are fully down when this is happening. The car seems to run the way it should, but the noise is annoying. Going about 40mph and throw it into 5th and the noise goes away, back down to 4th and it comes back. Any ideas or suggestions? It is also less apparent when there is a load on the engine, like going up a hill, and more noticeable when just coasting.

 

I now know where the noise is coming from. The clips that hold the ram air casing together are missing. Does anyone know where I can find a pair of clips for the air box? Check Hawks3rdgen, but I did not see them on the site.

 

Thought I had it figured out, but I took the air filter off all together and the whistle is still there. Would the maf cause the whistle? If not, what else could be making the noise. You can hear the noise even when the car is idling and you get the rpm's to 2000 or above.

 

Exhaust leak could be your problem.