EGR delete
Exhaust Gas Re-circulation occurs during light engine load, it's purpose is to reduce NOx emissions. Hot gases from the exhaust are vented back in to the intake of the engine instead of fresh air with a higher oxygen content. The hot exhaust gas acts in a similar manner to an inert gas under combustion conditions. The slightly inert gas causes a reduced cylinder temperature and also a reduction in peak cylinder pressure. The result of this is that less oxides of Nitrogen are formed during combustion (NOx). This is beneficial for the environment and public health however it does cause a lot of problems for an engine.
