[jg155]

I have just finished replacing the port seals and isolator bolts on my 2000 Windstar 3.8L. The CEL is now off (which is great), but I now have a problem with rough idle. When stopped or parked, the engine almost sputters and bounces between 500 and 800 rpm while at idle. When driving, there is no noticeable problem. I thought I might have left a vacuum line loose or off, but after checking several times I can't find any obvious problems. I checked the IAC to see if it was dirty but it didn't look too bad to me. What am I missing?

Any help will be greatly appreciated.