What the hell does the EGR do anyways?

 

EGR - Exhaust Gas Recirculation - Its for Emissions, it takes exhaust gas and reinserts it into the intake manifold. Anything that didnt get burned gets reburned, thus making it more efficent. Anything thats already burned wont burn again, so it keeps the cylinders cooler, and ensures that exhaust gas is "cleaner" before it goes to the cats. Making them work less to ensure good emission levels.

 

Didn't certain years have the EGR on the left side, then some had the left?

 

will these help with gas mileage?

 

just for the record mine has drivers side EGR. Blah