I have a 99 maxima se with 75k miles, when i start my car on a cold day it idles at about 1100-1200 rpm. When i put it in drive it shoots back down to about 600 rpm. Even after letting it warm up and driving for about a half hour, when you put it in park the rpm's shoot back up to 1100-1200 rpm. This is my first winter with the car so im not sure if this is normal or not. Also im starting to notice that when im cruising on the highway and i let go of the gas the car seems to studder or jerk. Thanks alot for any help!

 

It's normal when you first start the car for the RPM to be high like that (to warm the car up faster), but I don't think it should jump back up when you put it in park and it's already warm. It may be something the autos do though. I wouldn't know.

 

my auto does the same. but after the car fully warms up, everything is fine. if the rpms shoot up back to 11-1200, even after it is fully warmed up, then thats weird.

the 'letting go of the gas and getting a bit of a jerk', i believe i read it on another thread a couple months back, dont take my word, but it has to do with the torque converter. try clicking O/D off and see if it happens. but all normal.