Question: I have a 2001 Pontiac gran prix 3.1L engine. To accelerate I have to just press slightly on the gas petal. If I press to hard or all the way on the gas petal the engine will rev up to 4000 rpm but will no accelerated. Whether I am going slow or fast does not matter I have to nurse the gas petal to accelerate. When the car jumps up to 4000 rpm I need to release the gas petal then press lightly on it to accelerate again. The car will maintain its speed and rev normally when I achieve the desired speed unless I start going up anything other than a slight incline. Optional Information: 2001 Pontiac gran prix 3.1L Already Tried: Change fuel filter,EGR valve Spark plugs,wires 3 month old Answer: This sounds like your transmission is slipping. Check your transmission fluid level with the engine running and the vehicle in park, on flat level ground. If it is low, top it off and test drive. If it is full, then the internal transmission clutches are burnt and you will need to rebuild or replace the transmission.