2005 Mustang GT erratic idle

I love my car but, I'm old school and sometimes I'd like to take all this computer engine control crap and trash it! My car is running really rough. I got the trouble code from the computer P0506 which means "Idle Air Control (IAC) system, rpm lower than expected". I've worked with Idle Air Control valves before so I figured it wasn't to bad. Until I looked under the hood and didn't see anything that looked like an IAC, so I looked in the service manual and found out that there is no actual IAC valve it's part of the "Powertrain Control Module" Sooooo...Now what do I do. I really hope I don't have to buy a new modual because I'm pretty sure that a simple IAC would be a LOT cheaper. Can some one please help?

Have you tried cleaning your MAF sensor?

I got the same code right before my air filter fell off. I have a Demolet CAI and I cant keep the air filter on, when it starts to idle rough I have to go tighten the filter back up, or wait a couple more miles for it to get bad, then go put the filter back on. Anyone else with this? I was thinking some sort of adhesive...

Thank you for your reply. The MAF sensor was one of the first things I looked at, but I didn't realize you could clean it. So how do you clean it?

Spring washers are used to prevent screws from loosening due to vibration.

You can buy that are advertised as MAF cleaner at a Auto Parts store. There are other products that will work all. You can do a search for them.

^ There ya go. I haven't cleaned mine yet but should soon. I myself am curious what other guys have used to clean theirs.

First I would clean the MAF with either MAF cleaner or electronic parts cleaner (available at radio shack). Also clean the throttle body with carb cleaner and make sure that the blades aren't gummed up and sticking. Additionally, as skyhazard said, make sure that the intake tube fittings are tight.

If these steps don't take care of it, then you may have to replace the throttle body. Several people have had to do this on earlier S-197's. newtakeoff.com has them for $180, which is far cheaper than the dealership.

Thanks guys, for all your help!! I knew that I could count on the Stang Gang!

Don't do that. Carb cleaner is generally much stronger than something designed to clean throttle bodies. Many throttle bodies have a protective coating that carb cleaner will strip off. CRC has an aerosol spray that says it is safe for the protective coating on throttle bodies. Or use a product called Intake Snake, which has a sponge tip that contains a solvent that is suitable for throttle bodies.

My 2005 stock GT was experiencing a rough and surging idle when cold. I cleaned the MAF sensor (with MAF cleaner) and cleaned the throttle body while it was at it. Runs like new again now.