2002 neon idle

Mt neon idles very rough when it is hot outside w/o ac on. Slip it into neutral and back into drive it smooths out. Leave it in drive and idle is so bad it shakes the rear lip of the hood. I was told I need software updates from dodge anyone know about these. Cost etc.

yeah, the software updates will run you about $80 or so. Had my wifes Neon updated a few months ago ( also 2002 ) Supposed to increase driveability( smoother idle, accel, and trans shifts). Its a little better now, but summer is usually when i have the idle problems similar to what your describing but not as bad, so i wont know until then.