Exhaust Gas Recirculation Valve Description: Notes

WARNING: This page is about a different car, the 2006 Suzuki Verona. However, it is still accessible from the selected car via links, so may be relevant.

The Exhaust Gas Recirculation (EGR) system is used on engines to lower Nitrogen Oxide (NOx) emission levels caused by high combustion temperature. The main element of the system is the EGR valve, controlled electrically by the Engine Control Module (ECM). The EGR valve feeds small amounts of exhaust gas into the intake manifold to decrease combustion temperature. The amount of exhaust gas recirculated is controlled by variations in vacuum and exhaust back pressure. If too much exhaust gas enters, combustion will not take place. For this reason, very little exhaust gas is allowed to pass through the valve, especially at idle.

The EGR valve is usually open under the following conditions:

Warm engine operation.
Above idle speed.