Ford Mustang/Cougar 1964-1973 Repair Guide

Exhaust Gas Recirculation System



All 1973 models are equipped with an exhaust gas recirculation (EGR) system to control oxides of nitrogen. Because the system channels exhaust gases through narrow passages into the induction system, deposits build up quickly in the system, eventually blocking the exhaust recirculation flow. Therefore, to keep the car's emission levels up to federal standards, it is necessary to service the system at the recommended intervals. EGR service consists of cleaning or replacing the EGR valve, and cleaning all of the exhaust gas channels.