So just pulled into the driveway, put it in neutral, turn put on the handbrake, take foot off brake so handbrake is holding the car, foot on brake again...about to put in park and then i see the engine is reving between 450-750 with the needle bouncing up and down whilst car is in neutral- thats scary

I put it in drive - and then back into neutral it was normal

 

the same thing happened to me awhile ago

 

when that was happening, how many times was it bouncing up and down approx?

 

It happened after i pulled in the driveway, after slowing to a stop i engaged the handbrake and then shifted into neutral - thats when the revs started bouncing - continually - until i shifted back into drive again

 

not too sure but it may have something to do with the maf sensor.... i have experienced the same thing you are talking about in my ralliart as well when my buddy let me drive his evo x for a day.. ( we traded cars ) so anyway 2 days later my friends maf sensor went bad... he only has 19k on it and had to replace it 160.00 bucks.. I heard al lot of sensors are going bad in evo x there is a thread about it around here somewhere.. i have not had my go bad yet... if that happens your car will idle at 2k and be careful cuz boost will spike at 30+ so dont drive too much..