Catalyst Protection System

Chrysler Corp. models manufactured in 1975 use a throttle opening system to protect the catalytic converter from excessive heat generated during high speed deceleration. The system consists of a engine speed switch and throttle opening solenoid. The speed sensor receives an engine speed (tach) signal and opens the throttle whenever the engine is above 2000 RPM. See TESTING and ADJUSTMENTS  in the article for more information.