hello i have 00 civic si b16a2. when i down shift into neutral at a light my car dies. like the idle needs to be adjusted or something is about to go?? can anyone offer any insight. car drives fine other then that.

 

I would check to see if you have any cracked or disconnected vacuum lines.
Just fixed a friend's Ford Escort with the very same symptoms. Had a cracked vac line to the pcv valve.
Good luck
Mike M.

 

note ive also started the car a few times and it would do the rpm surge but that subsides quickly (still sound like a vacum line?)

 

check my ongoing thread:
https://honda-tech.com/zerothread?id=1975745
Start with all the stuff that I list as what isnt my problem