idle when in part

[Midnightride]

ok this is on a 95tsi automatic.

basically it has done this since I have owned the car.

idles fine at lights, stops, etc... but after driving it and you get to a stop, put it in park and let it idles for say 25+ seconds, check engine light comes on. You can reset it and as it wont come back on till you let the car idlea in part for the 25+ seconds. if you turn the car off right away or say 5-10 seconds after driving it, it fine. Idle in park stayes at about 1000rpms then when the light comes on it goes to say 1300 or so.

is it the throttle position sensor or idle control sensor. Not sure if we even have a idle control sensor. Or could it perhaps be something else?

someone mentioned might have to do with the tranny since its only doing it in park.

any suggrestions?

 

[95blackGsTurbo]

Idle won't usually throw a CEL. I would suggest taking it to a parts place or mechanic quick and having them read the code to see what it is. It will be your easiest bet. Parts store's usually do it for free if they have the equipt. Some technicians will do it for free if you ask nicely. Could be a random misfire code you only get at idle or a sensor. Hard to tell.

 

[Midnightride]

did that before, it always throws the same code.

if i remember, its one of these or perhaps all of the. just think its weird that it only does it when it idles in park for over 25 seconds.
1) Fuel trim malfunction (p0170)

2)Manf control veh. speed (p1500)
Idle speed control
Auxilary inputs

3)Idle control system malfunction (p0505)

 

[jabinya]

I have been having the same problem as you. I have a automatic as well. Also my CELs are identical to yours. It all started after I installed my 60mm throttle body and Aeromotive fuel pressure regulator.

Have you done any modifications before this problem started?