[Rackshaw]

Just got the oil changed. I brought the van home and pulled into my garage and put the Van in Park and the engine started idling back and forth between 1k and 1.5 k, but no check engine light. Turned off engine. About 30 minutes later, took van back out to driveway, put it in park, started to idle back and forth, check engine light came on, then idle hovered around 1.5k and TCS light comes on. This happens only in park. 2001 LX, 145k, warranty tranny at 100k

 

[William Wiles]

Get the code read. It is the only way to isolate the problem.

 

[gregersonke]

Sounds like an EGR code will come up or an Idle air control.

Either way, the problem is usually some combination idle air control and EGR port being clogged. If you fix it at a dealer or shop its all around 500 bucks.

 

[Rackshaw]

Code is P0505. From what I've read so far, it's probably the IAC valve. However, the concerns I have is that the idle only jumps when in Park or Neutral and the TCS light comes on only after 6 minutes of driving or several iterations of idle fluctuation when in Park or Neutral. Also if a vacuum line was dislodged during the oil change , could that be causing the P0505 code to come up?

 

[Rackshaw]

Took it back to the shop and they confirmed it was the IAC valve. $351 ($187 for parts!) later, all is well. Alas it's only money.

 

[Gary Bakalik]

Forget the dealer and the $300-400 for a P1129 or P0505 code and do it youself! If you can flip a wrench and have about 45 minutes you can do it and the part (IAC) will cost ~$85 from Autozone. The toughest part was removal of the 2 phillips head screws that hold the IAC to the throttle body. I used needle nose vice grips and it workrd great! Good luck.