ddg1025

Okay when its idling and you tap the pedal a little bit it revs up further than you hit the pedal then stays there for a couple seconds and comes back down to normal idle. When your driving it and your shifting into the next gear it pretty much holds the rpm its at when you let off and push in the clutch.

Im thinking it might be a vacuum leak. Im not sure if thats common with the plastic intake. Im not familiar with the 4.6 this is my first one.

Its also through check engine codes for a lean bank 1 & 2

uberstang1

Check the IAC and the TPS as well.

ddg1025

How do you check the IAC is there a test procedure

PROMETHEUS PRIME

SOunds like a IAC valve sticking on you.

Some people clean them with carb cleaner after taking them off. I would do this and if it helps just replace.

Dave19525

I had the same problem. Replacing the iac may fix it. It the tech and how to sticky there is a mod you can do to the iac gasket that fixes the problem. In my case it made it idle a little too low so i made the hole a little bigger. Also I cut a regular size hole on the side of the gasket that is normally blocked. Now when I get ready to get emissions test all I have to do is pull the gasket and flip it over. After the test I just flip it back. I tried to add the link to the article below hope it works for you.


https://mustangforums.com/forum/4-6l...ging-rpms.html