have imprza 1995 uk car, when i put my foot on gas i can ear air coming from the dump valve, have been told there is air leaking somewhere, i have tried looking to see where its coming from, cant see nothing. would this effect the perfomance of the car in any way? anyone had a simular problem? or any advice will be gratefull.

 

If it's an aftermarket DV it will be affecting your performance either way. Take it and throw it in the bin and fit a standard one.