2004 Range Rover HSE Throttle Lag. Any help?
 

I have, in the last 3 months, acquired my 2004 range rover hse and have found some issues surrounding the throttle reaction time. I am looking for something to either let me tune it to have a snappier response time or possibly a part i could buy to improve the throttle lag. For example, as to the measure of the situation, sometimes when entering a highway I may be going 45-55 MPH into a 70 MPH and when attempting to quickly accelerate it may take up to 5 seconds to get up to speed with the pedal to the floor. Has anybody else had excessive problems such as this?