HI got a range rover p38 (2000 reg) Lpg\Petrol 4.6 i recently installed a amp in to my radio\cd player, wish i had'nt now as when i am listen to the radio drivin everything is all right sounds great even wen i rev but if i switch to my cd player, i get a wistle noise and when i rev it goes...

I have a Range Rover p38 4.6 petrol\Lpg (2000 reg) The car runs great in Lpg like a dream but as soon as i switch to petrol or start in petrol the car just crawls along and has no power at all (Under load). When the car is standing still under no load it revs well and seems to be no promblems...