2002 Acura TL Type S P0505 code
 

2002 Acura TL Type S P0505 code, I have replaced idle control module and pcv valve and still does the same.

With brake on in drive at a stoplight the idle will go down to about 400 rpms idle rough then VSA and Check eng light come on.....after that the car will shudder and jerk if you let off thottle fast at most speeds.

Check your alternator, if not that, then it is iac valve.