EGR Valves - Explanation

EGR Valves

Explanation

EGR stands for 'Exhaust Gas Recirculation'

Basically, its job is to take exhaust gasses and pass them back into the intake to be burned again. This reduces overall emmissions, but is not good for performance and mpg.

For example, suppose that 1 cubic cm of air contains 1 million O2 (Oxygen) molecules, the combustion process in the engine uses up some of these O2 molecules and you're then left with the exhause gas, say it only has half of its original amount of O2 molecules.

As you know, the more O2, the better something burns. Same principle as in an engine. So by removing the EGR, the car takes in more fresh air and therefore more O2 molecules resulting in a better burn and thus more power. This is also more efficient as you're getting more power for the same amount of fuel.

A properly working EGR also reduces combustion temp - helping to prevent damage by quenching the air/fuel mix with the recirculated exhaust gas

Submitted by panda and WeeGee