Electronic Sonic EGR Valve
This valve operates like a ported valve, except tapered pintle is used for more exact flow control. Sensor mounted on top of this valve sends out electrical signals that tells Electronic Control Assembly (ECA) how far EGR valve is open.
ECA then signals EGR control solenoids to maintain or alter EGR flow as required. Source vacuum is from manifold and is bled off or applied to diaphragm by ECA. A cooler is sometimes used to reduce exhaust gas temperature, reduce detonation and allow better exhaust gas flow. This valve operates only at part throttle mode. It is closed in all other modes.