Exhaust Gas Recirculation: Description and Operation: Overview

In this system, exhaust gases are circulated to dilute the incoming fuel air mixture. Dilution of the incoming mixture lowers peak flame temperatures during combustion and thus limits the formation of NOx.

Fig. 40 EGR valve & Backpressure transducer assembly. 4-153 & V6-181 engines:

On 4-153 and V6-181 engines a backpressure type EGR system is used, Fig. 40. The backpressure transducer measures the amount of exhaust backpressure on exhaust side of EGR valve and will vary the vacuum signal to the EGR valve to provide proper exhaust exhaust gas recirculation under all conditions.