revs wont drop
 

for like the last 2 days when puttin the car in neutral or puttin the clutch in the rpms have been jumpin up to like 1800 and stayin there for a while and then gradually coming down .. it got like this everyonce in awhile after runnin it hard but just for a little and i havent ran it hard at all recently and its doin this a lot ... any ideas??

Clean your MAF and your IAC

vacuum leak

IAC x2