loss of power

[Asaneale]

my 04 1.2 16v clio has dveloped a huge power loss. on idle i can hear a air leak which gets louder when the accelerator pedal is pressed, and then returns to "normal" when i let go it idles fine and doesnt sound rough. anybody had similar problems or any help would be much appreciated

 

[Asaneale]

could it be a inlet manifold problem as even when driving at 50mph the leak was barely noticeable untill i use the accelerator.