[maxwedge]

Yes, it is working manually. The map sensor sends a signal to the pcm when the egr operates and the the pcm calculates that the drop in engine vacuum as a result based on throttle opening, that the egr is working. This may require a full scan to confirm what happening or not happening. It is possible because of the lack of designed exhaust back pressure from the headers and dual, that the egr is no longer effective.