Hi, Maybe you can help. My check engine light came on, my mechanic hooked it to a machine and said i had a code (forget the number) for egr flow problem. He reset the light and told me to drive, i drove like 80 miles and its on again. The car runs fine, i cant feel a difference. What is egr and do i need to fix this?

thanks,

William

Hi William,

EGR stands for Exhaust Gas Recirculating.  The egr valve introduces exhaust gas into the intake system.  Exhaust gas being an inert gas, actually lowers combustion temperatures, and helps prevent the bad exhaust gas NOX.  It also helps keep the car from Pinging up a hill.

Since Exhaust gas is exactly that, the egr valve and the egr passages get clogged up with carbon, and cause the egr valve to not close properly, and causes the egr passages to get a carbon build up restricting flow.  Your mechanic can remove the egr valve, try and clean it out, clean out the passages on the intake, and reassemble.  This works pretty good.  Sometimes the egr valve needs replaced.  Best have him clean everything out, clear the computer and drive the car about 100 miles and see if it resets the light or note.  The car only tests egr when your cruising, so you need to put some miles on the car.

Hope this helps

Bob

Paul's Motor Car Service