I have a 98 accord coupe with v6 & 63,000 easy miles on it & today , after the car had not been used for 12 days in frigid northeast temps the idle started to surge between 800 rpm & 2000. It lasted about 15 miles , then the check engine light came on. A few miles later the idle went down to normal & stayed there. A code 505 IAC was set. I erased the code & it seems to be OK. I priced a new IAC @ the dealer & it retails foe 221.00! I asked the parts guy if he sells many & he said YES I DO. Hopefully its for very high mileage vehicles otherwise it doesn't speak well for Honda (Denso) quality. How difficult is this to replace? IT looks pretty simple. I have the Honda service manual for this car. Does it seem like an isolated incident or will the surging reappear? Thanks for any info!!

The sticking IAC is very common on V6s.

You can attempt to clean it. Do you have compressed air available to you?

In order to change it you'll need to remove the throttle body (leave cables attached) and flip it upside down. Clamp off the two coolant hoses that go to the IAC so that you don't leak all over. Have the two throttle body gaskets handy, you may not need them if they don't rip.

Cleaning can be done with it on the car, remove the intake duct from the tb and the air cleaner.

Look in the throttle bore, you'll see a rectangular hole in there. Spray a good 5 second blast of carb cleaner in there. Let it sit for a minute or two. Then use compressed air to blow into the hole, WATCH YOUR EYES. Blow it out and fill it again. Repeat. Hopefully this will free it up.

You can turn the key on and off while it has the cleaner in it. The valve closes down and opens fully when the key is cycled off.

Once done, put it back together, you may have to start it like it's flooded, but it'll start. If the surging is gone, consider yourself lucky. I've not had much luck doing the cleaning.

Seems like it must be a common problem. My friends 03 Pilot just needed one last week. 120k miles.

If you have to buy a new one check out some online dealers like bernardiparts.com and college hills honda. Their shipped prices were lower than what my local dealer quoted.

My co-workers 2001 Acura MDX, just needed one (at 120K).