My renaultsport mats caught under the clutch pedal when i first fitted them.
I was getting like a flip flap noise, took me a while to realise what it was, when you pressed the clutch pedal down it touched the end of the carpet which then stuck to the pedal, as you moved your heal, the carpet it like, flapped down.
Cured it with a little strip of velcro on back of carpet.
Mines a cup, no metal pedal covers if that makes a difference.
If it's the Accelerator then it does have a ''step'' sort of action part way down, there's a button underneath it, something to do with the Cruise Control I think...