my idle is about 650 or so and thats normal but if im going down a hill and put my manual into nuetral the idle will stop at 1200 until i slow down to about 15. also between shifts the idle willl shoot up. if im in 2nd and shift at 2500 it willl go to 3000 before going down to 3rd at 1900. could it be a bad maf sensor??

look into the dashpot at the throttle linkage. Looks like a minature cruise control with a piston that comes out and buts up against the linkage with an adjusting screw. This is supposed to ease the throttle back gently when you let up on the pedal so it doesnt backfire. Yours maybe going bad. The adjusting screw is tricky - best take it to the dealer.