My friend has a 2003 Honda Odyssey. I checked the codes today and P0505 and P1129 came up. The check engine light and TCS lights were on, and the idle was surging up and down at idle.

Is this a common problem or is there a TSB on this issue? What should I check/replace?

Thanks!

 

Clean or replace the IAC valve and clear the codes. Very common issue.
For the heck of it check the power steering switch wires at the bottom passengers side of the engine bay too.

 

I took off the IAC valve and reset the check engine light last night. Upon first start, the engine was idling fine for about a minute then started hunting up and down again.

Would replacing the IAC valve fix this hunting idle problem? How can I test the old one to make sure it is faulty?

What am I looking for as far as the power steering switch wires? If they are disconnected? What would that have to do with the problem?

 

You'll need to replace the IAC then.
If the wires are broken the van will idle up and down but more randomly.

 

What size socket or wrench is needed for the one bolt?

 

I need to either clean or replace my IACV... but I can't find it.

Can you post a pic of where it is? I have taken pitcures of my van and you can view them here... http://picasaweb.google.com/Iamtheitguy/VanOdyssey2002

 

the IAC valve is located under the throttle body. check for broken power steering pressure switch wires....

 

yeah I found it, but since it is upside down to me I don't have what it takes to get it off... but where are the power steering wires you mentioned?

 

The power steering pressure switch can be accessed behind the passenger's front wheel. If one of the 2 wires are broken, you can get an erratic idle while stopped. Check the connector and the wires. Here are some pictures of the PS connector:

http://www.odyclub.com/forums/attach...&postid=291641 the harness is disconnected here.

http://www.odyclub.com/forums/attach...&postid=349850 one of the wires are broken here.