Exhaust Gas RECIRCULATION
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Suburban, and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The Exhaust Gas Recirculation (EGR) system is used to reduce the amount of Nitrogen Oxide (NOx) emission levels caused by combustion temperatures exceeding 1500°F (816°C). It does this by introducing small amounts of exhaust gas back into the combustion chamber. The exhaust gas absorbs a portion of the thermal energy produced by the combustion process and thus decreases combustion temperature. EGR system will only operate under specific temperature, barometric pressure and engine load conditions in order to prevent driveability concerns and to increase engine performance. EGR is a linear type and is located on top rear of engine. See Figure .