HELP!!modded corsa sounds nasty

[n4z1gunda]

i got a corsa which is kitted up and propa loud with the exhaust sytem, but a month ago i start getting a nasty diesel sound, like an exhaust blwing, i got it checked by garges bt they cudnt figure it out, took it to exhaust uk and they confirm it not the exhaust system at all or an exhaust gasket thats all k.the sounds sees to cum from underneath the engine front but its also not the engine, i gt toll it cud be the hoses,WHAT HOSES???? ne1 help the sound cumz wen im ragging the car like country lanes or js above 40.dn if i stoip n rev ithe sounds there.bt if turn car off and onn the soundd goes till drive cuple of miles.it hard to explain ope sum1 can help

[overheater987]

once again in english