Custom EGR block-off set Brand Custom Website - Part number - Exhaust gas recirculation (EGR) is a system fitted to all GT-Fours, except the Japanese models. It leads a certain amount of exhaust gasses back into the intake manifold to create cleaner exhaust gasses. I however don't want dirty exhaust gasses in my intake and by fitting block-off plates you can prevent that from happening. Removing the EGR system also creates extra room around the engine. Related links Modifications - Engine