EGR System: Operation

Under various engine speed and operating conditions, regulated vacuum to the EGR control valve by various components of each model, allows measured amounts of exhaust gas into the intake manifold. This reduces the air/fuel combustion temperature and reduces the amount of oxides of nitrogen (NOx) in the exhaust gas.

Fig 1: EGR System (Non-Turbo)

Courtesy of MAZDA MOTORS CORP.

Fig 2: EGR System (Turbo)

Courtesy of MAZDA MOTORS CORP.