Had installed a greddy evo 2 exhaust a few months back, but the exhuast is making some squeaking sound when i cold start my car, and whenever i remove my foot from the gas pedal; but than the squeaknig noise will disappear whenever my car is warm up. Any idea why this will happen?

 

Sounds like cold joints. It may just be the weather.

 

had this experience with other exhausts on other cars. sorry, never found a cure. just had to get through the gears a couple times, they would warm up noise dissapeared

 

It is probably hitting the rear sway bar.

 

I have the same greddy evo 2 and I think that your car is doing the same thing that my car does . It will make a very small whistling noise until it warms up ! Hope that helps !