'01 high idle problems

hello everyone,
ive been reading this forum for a couple of days now and ive found alot of useful info.so first let me say thanks:)... anyhow heres my issue on my '01 plymouth, the car is a 5 speed with 71,200 miles and when i downshift and put the car in neutral at stoplights it revs pretty high for about 5 to 6 seconds then lowers to a idle to low kinda skippin up a little and down a little. i just got this car a week ago it drives great other than this problem which is pretty uneconomical on gas plus pretty damn annoying.since ive had this car ive changed the spark plugs , oil ,and air cleaner.also i did the code thing and got p1294(idle thingy)... any ideas??? thanks in advance for the help

any ideas?????/
cmon help me out on this one please

ty to all who took time from theyre busy days to help me out with my problem. you have all been very helpful.:disappoin

may just need the computer reflashed could have a bad tps sensor or the connector may be melted at the tps

yeah, im w. ya on the TPS sensor. my bad, i usually dont go on this forum too much.. i got a 1st gen neon, not the 2nd..

also, check for vaccum leaks.. those things will cause that fluctuation too.