EEC
(electronic emission controls)

---

are in in automobiles, computerized engine operating controls that reduce automotive exhaust emissions of carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC), primarily by optimizing combustion efficiency. This is accomplished by automatic monitoring and control of key engine functions and operating parameters, such as air-fuel ratio (see combustion), spark timing, and exhaust gas recirculation.

Also see emissions (automotive), hydrocarbon emissions.