I had a look into the EGR on my car. I blanked the small actuator pipe to see what effect it would have. It did seem to make the car seem more responsive at very low revs (very slightly) but other than keeping the gunge out of the intake not much benefit. I have thought of making up a bypass tube to replace the whole EGR unit with a straight tube as the EGR looks like it would restrict the airflow quite alot but it seems like a lot of work for potentially small benefits.