Your 1975-1982 C3 Corvette's EGR Valve reroutes some of the exhaust gases which are emitted by the engine into the combustion chambers. This effectively reduces temperatures in your C3 Corvette's combustion chambers. It is an important component in the exhaust fuel recirculation process as it helps to prevent exhaust valves from overheating.
A faulty EGR Valve should be replaced immediately for the sake of your C3 Corvette's performance and emissions. Symptoms of a faulty EGR Valve may include the following: Inefficient combustion, hesitation, rough idling, stalling, and knocking.