Q: How is the Exhaust Gas Recirculation (EGR) system and EGR Valve maintained and diagnosed on Ford Bronco II?
A: NOx formation is reduced and combustion temperatures are lowered by the EGR system through reintroduction of exhaust gases into the combustion chambers. Engine speed, vacuum, exhaust backpressure, coolant temperature, and throttle position are some of the factors that determine how much exhaust gas is reintroduced. The EGR valves are vacuum-operated and a vacuum diagram is supplied on the VECI label. The PCM can be used to control PFE or DPFE systems consisting of hoses, EVR solenoid, EGR valve, and either PFE or DPFE sensor. Look for damages on gaskets, hose connections, and valve mounting among others. Check whether there is an intermittent connection in the electrical connector to the EVP sensor. If so, replace it. For a diagnosis of poor engine performance related to EGR system concerns permit access to scan tool data and perform self-tests on all systems with electronically controlled components. Monitor idle speed with the IAC solenoid disconnected while applying a vacuum to the EGR valve to assess its operation.