Have you checked your emissions setup like this? MPGs good?
I checked my EGR function tonight - applying vacuum kills the engine like the FSM says it should. It didn't seem to respond to applying and positive pressure, so that's good.
One of the modulator tests - air flow through Port Q test below and above 2500 RPMs seemed to pass fine.
However, I was unable to get any vacuum between the modulator and the EGR when the engine was hot, at any RPM. I might have c*cked that last test up, so I will try again tomorrow in the daylight.
Unless I decide to go down the EGR delete path, it looks like I need to re-check the vacuum system - not for leaks but for commanding the wrong airflows through the VCV or a dead VSV.
I have learned more than I never wanted to know about emissions controls...