If you ran higher octane fuel.....maybe.
The EGR is used to lower NOx emmisions, high NOx emissions come when cylinder runs too hot, like when accelerating or driving up a long hill.
High NOx emissions started when spark timing was advanced more for better performance and MPG.
This extra cylinder heat causes "pinging/knocking"(pre-ignition) of low octane fuel.
In the past engine spark timing was set earlier so spark happened before pre-ignition could, but power and MPG is not as good this way.
Since computer controls spark timing you can not reset it for less power and lower MPG, so if EGR is removed Regular gas will "ping", so you will need to run higher octane fuel.
Pinging causes piston and valve damaged.
IMO, there is no gain, and only a downside to removing EGR system.
Last edited by RonD; 06-17-2014 at 03:53 PM.