Since having the car mapped it whistles under load (4th or 5th), well its more like a quick sharp intake of air briefly at a certain boost level, it comes in very quick, and stops very quick too. Its not a spooling sound and it defo dosnt sound right, and i'm having a right nightmare finding it as it dosnt do it while stationary. I ran the car without an air filter and the whislte lastted longer so i'm thinking airbox/intake issue? Checked all the hoses and everything seems ok. Anyone else have this or know what it is? Only mods on the car are K&N panel and Custom-Code map.