Originally Posted by
pmkls1
If you take a moment to remember the theory of how EGR is supposed to work it helps to understand when it may be helpful and when not. The function of EGR is a crude way of reducing engine displacement and fuel consumption by pumping a metered amount of inert exhaust gasses into the cylinders under light engine loads when the demand for power is low. Still, different engines are going to respond to when the EGR is enabled and such differently. I personally have always disabled EGR functions on my vehicles for simplicity, but it can be useful.