EGR valve

What is the main function of the EGR valve, because it is formed, which are its characteristics, handle fuel or exhaust gases or both.

Thanks for your participation

hi, friend. The function of the EGR is to pass a certain amount of combustion products from the escape system to the admission. When using this method decreases the maximum temperature of the cycle, since in correspondence with the amount of burned gases decreases the amount of fresh load.
To a certain point, the increase in the residual part can affect positively on the transformation of energy and, with it, on fuel consumption.
The EGR valve receives control signal from the motor management system.
The EGR valve works for partial loads and cuts the recirculation into operational points established by the designer (rotation less than 1200 rpm, motor temperature less than 80 ° C, etc). I hope it serves you

The function of the EGR is to recirculate the exhaust gases, in the case of cars such as the Malibu, when it is covered by excess of Ollin, the car loses a lot of power, and in the case of fuel gases, the manager is the EVAP valve

As far as I understand the EGR reduces power to the engines, I don't know if this is incorrect is what I have heard

If you reduce the power, then why is it equipped in all vehicles?