I know this is probably a dumb question. I have noticed that if I try to rev the engine when it is in park/neutral, it will rev but then I have to wait for the RPMs to go back down before I can rev it up again. If I press the pedal down twice real fast, it will rev on the first press but do nothing on the second. I have a 2005 WK 5.7. I was trying to hear if I had an exhaust leak because I thought I heard something that sounded like it the other day I was driving it. Thank You!