Quote Originally Posted by koxxwasp View Post
snip...

I also hear from a good diesel fitter that the EGR is there for a good reason and that I should leave it, I am not a mechanic and this is the first oil burner I have had, so why if Nissan spend millions on development and have all the little intelligent engineers do we (the public) think we know better?

You all seem a friendly lot and pretty clued up (far more than me) I am learning heaps on here, however I still think things are better left alone if they are good to start with.

Please don't think I am being smart, I just want to get everything straight before I go messing with her.
We don't "know better" as such. The issue is that the Nissan Engineer has to work within the constraints of the laws as they exist. EGR being a case in point.

It is essentially only there as an anti-pollution measure but the trade off is that the engine "swallows" a whole heap of contaminents etc at the cost of accelerated wear and performance. Indeed that is why EGR is blocked by the ECU and Engine management at higher engine loads

Blocking the EGR is great for the engine but terrible for the environment.