I drive a 04 Evo GSR. When im casually driving, as in shifting around 3K, it doesnt happen but I noticed when its over 5K I noticed that as soon as i let go of throttle and depress the clutch, my revv wants to go all the way up to 7K. It also wont go back down untill I release the clutch into another gear. I'm thinking it is a vacuum leak somewhere. Has anyone have this problem before? If so, how'd you fix it?

 

Hmm...It shouldn't be revving without you pressing the gas. Sounds like you're not letting off the clutch early enough when you're driving it like that.