I was on my way to Kennedy Commons last night and as I was leaving my house I came to a red light, threw the clutch in, put it in neutral and my revs stayed up around 2500-3000 and wouldn't drop. It happened once before about 2 weeks ago when I took my car around the block without a hood on. Both times I turned the car off, started it back up and everything was dandy. Any ideas as to why its doing this?