Blocking the EGR Valve

[Chaz]

Sounds like a lot of positives, but are there any known negatives?????

Nothing too serous in the way of negatives.

The Di will boost a bit higher and needs to have boost adjusted so not to have limp mode on full throttle. The CRD has better control over boost, but does sense pressure on either side of the EGR valve and will give a fault light and code when it sees a pressure differential. The answer is to drill a very small hole in the blocking plate to equalize the pressure and restrict EGR flow, or fit a Scangauge-II to clear the fault code each time it comes on.

That's it apart from what Tony has mentioned. The positives far outweigh the negatives.