Let me re explain my theory a bit better.
Standard egr takes gases from the exhaust to the egr, the egr valve opens at certain points an draws in air from the exhaust and puts dirty exhaust gases into the engine to ease emissions. Egr valves clog up from all the crap out of the exhaust... So we resort to blocking them as emission tests are not done on a diesel so no not fail.
When blocking the egr with a plate you stop the shit gasses getting in... But the valve can still operate and still wants to take in air but we have blocked it so this stops air and can cause a diesel knock.
My theory is rather than no air going in at the egr at all.... Why not swap exhaust air for fresh clean air..... So stick a universal enclosed induction kit onto the egr so when the valve opens it eats lots of nice new air.... This should mean no diesel knock... No dirty air. .... Clean efficient burning.... Better economy and more power.
My question is what to do with the other end.... If you block it your causing more pressure in the exhaust system which could mean more back pressure to the turbo... So if we fit some kind of valve similar to that of a dump vale/ waste gate that way of pressure gets to high it can just release it out