2003 Ford Explorer Having Idle Problems

I've got a '03 Ford Explorer Sport Track that has been having idle problems for some time now. The scanner keeps showing No.1 O2 sensor lean and No.2 O2 sensor lean. The IAC motor has been changed, the O2 sensors have been changed, the spark plugs and the coil packs have been changed but the result is the same. I've capped off the brake booster vacuum line and no change. I also capped off one of the other vacuum ports but no change. It idles rough but when you drive it it runs just fine. Any suggestions would be greatly appreciated. Thanks, Jerry