Idle Air Controller.
I just found this:
There's a thread on VTF addressing this issue

 

Ihad a ride to the dealer today and there was codes p-0131 and p-0151,the tek showed me how to clear the codes and since it only happened twice I was told not to worry. It will correct itself each time the ign. is turned back on and until it happens more frequently they will not be able to identify the bad.However if I want to have it checked they will do it,,so I'll wait a bit and see.

BTW that was very informative LilBudyWizer ,and kk6pg it looks like I'm right there with you! TanX guys!!

 

While that is cool info (and thanks for looking it up) 99.9 percent of the time it works great.....for now , but there should be no dirt there it's still ne.....I'm going to check the iac doo dad when I install my AN big sucker next week!

 

Ghost, thanks for making me look it up. I wouldnt have done it without you.

Best I can figure, its the crud buildup in the throttle body from the breather, not by dirt passing by the air filter. I had a problem with the air filter plugging at around 3000 miles, and when I replaced it, I noticed the crud. I didnt think much of it at the time, but now my mind has changed a little about it. Think its time I hosed out the throttle body.

 

Well what shall we use to hose it with? Carb cleanr or brake cleaner.I think either will do as they are both quite flammable. And now with my big sucker the excess oil will be directly sucked back int the throttle body whereas with stock air cleaner it gets spread on the filter itself.

 

I'm thinking along the lines of Gumout spray carb cleaner. Brakekleen may have stuff in it that you dont want in your cylinders. It's one thing to put a little extra Naptha and Petroleum Distillates in there. It's another with chlorinated anything.