I did an Escape throttle body swap about a week ago and everything worked out fine, results seemed pretty good etc but, I hadn't been driving my truck much untill the last couple days.
If I reset the computer the truck drives perfectly normal for like 15 miles then I get a CEL 1506 and 1504 and it starts idling high at stops (between 1300-2000rpms). I changed my IAC thinking that I could have messed it up during the process but that didn't do any good, still getting the high idle and CEL.
The 1506 CEL is IAC overspeed error and the 1504 is IAC possible vacuum leak. I took everything back apart and check all my connections and gaskets and it all looks fine so I'm kind of stumped on this one. If anyone has any ideas I would be greatly appreciative.

 

Is the Escape and your truck the same year? CEL means Check Engine Light. My Code library tells me that the P1506 redirects me to P0507 which is "Idle Air Control System RPM Higher Than Expected". I don't know if that will help you out. Good Luck!

 

Yeah, it was from a 2001, and my truck is a 2002 but thats not the problem. I'm thinking it has to do with the IAC port being shaped slightly different. Still not sure how to correct the problem though. The other strange part of the problem is that it only starts idling high after I drive for a mile or so, when I first start the truck and I'm sitting in the driveway it idles right at 1k where it always has.

 

Well, I figured out why I was having the idle issue. The gasket I made had a void where air was slipping in from the throttle port to the iac port. Made a new gasket and all is well. Idle is perfect again and no CEL's.

For future reference for anyone doing the Escape throttle body swap, make SURE that your gasket properly seals the IAC port off from the throttle plate port and you should'nt have any problems.

 

If you happen to have this problem come back, I would suggest taking some electronics cleaner to your TPS. Mine did almost the exact same thing, and after cleaning that sensor, it was perfectly fine.