This is a common problem on the 99's, but when this happened in the past it would stick round 1500 rpm then i'd tap the gas pedal it would unstick. Now today years later from the start of my drive home to the end every time I would shift and in that gap of neutral the car would hold at 2k rpm and hitting the gas pedal would not do anything it was very scary. As it did it the whole ride home and then in the garage turned the car off turned it on and it idled fine, but did roll it out of the garage and I did put in in reverse to see if if would stick and it didn't so people with experience please help me!!!!!!!!!!!