Engine Performance (A8)Question 109 of 120
The exhaust gas recirculation (EGR) system reduces which emission by lowering combustion temperature?
a.Carbon monoxide (CO)
b.Oxides of nitrogen (NOx)
c.Hydrocarbons (HC)
d.Carbon dioxide (CO2)
Explanation
EGR routes inert exhaust gas back into the intake to lower peak combustion temperature, reducing the formation of NOx. A clogged EGR passage can cause knock and high NOx, while a stuck-open valve causes rough idle. Its operation is monitored by OBD-II.
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