So check engine light has been on. Truck Idle's weird, it will all of a sudden rev up to 2000 rpm's. Computer scan codes read, O2 sensor heater circuit (bank 2 sensor 2), and Idle Air Control-overspeed error. Guy at oreily's told me he bets the O2 sensor is bad and causing the IAC to go to fast, which should be making me run rich. Does this sound right? Or what do you think the problem is.

 

had same problem with my truck with the IAC on a 99 5.4l f150 all i did was remove the iac use some carb cleaner and cleaned the iac really good and put it back on and has been fine ever since. this was 2 years ago. hope this helps. if you do a search on this forum about iac problems there is alot of info about it. i doubt its your sensor causing the problem.

 

x 2

 

Can somebody tell me or show me how to remove and clean the IAC. Is it easy to do? I'm mechanically stupid, so I need some help. I'm going to try to find some pics online, but if someone has some good ones can you give me a link. I have an aerosol can of carb cleaner, but I dont know if it is intended to be used for internal carb parts. Is this the stuff you are talking about? Or what kind of carb cleaner should I use?

Thanks

 

Also, when I type in "IAC" in the search, I get no results.

 

This is what it looks like from the bottom side and the 2 holes to the right are what needs to be cleaned.

 

Took off the IAC today and sprayed it with some carb cleaner. Have no idea if it helped or not. But if it worked my check engine light should go off soon, right? IAC valve was $82 at napa, and they didnt even have it on hand. I Think its cheaper at oreilys incase anyone is wondering.

Is it possible that I maybe need a new 02 sensor as well...?

 

How is the idle now?

 

Well it did the rev up thing inconsistently before, so its hard to say. Light is still on, and the idle still seems to adjust slowly. Like when i start the truck it revs up to like 1500-2000 rpm and it seems to take too long to drop down to 1000, instead of dropping to 1000 right away.

If I let it just sit in neutral and idle though, it usually sits around 1000. So is it not the IAC? My truck is also making a loud muffled ticking noise when i get on the gas now. Only thing I have changed on the truck is that i have a k&N air filter in the stock box. What is the loud ticking sound coming from the engine? Its only when I get on the gas.

 

Does the chugging noise mean I have a vacuum leak? Or could the IAC Cause a chugging sound too? Pretty much all the time when i drive for the last few days the truck makes a pretty good chugging sound, especially when i accelerate.