Originally posted by haitred
LOL, pardon me fellas, but even though you said what it stands for, I still don't know what it is and I'm interested cuz my check engine light just came on on Sunday. Good lookin!
If you mix a little bit of exhaust gas in with the intake charge, it lowers combustion temperatures. That lowers NOx without raising CO & HC. Most engines need just a little bit of this to pass emmissions. Your ECU opens & closes the EGR valve, but if the EGR ports are plugged with crud, then it doesn't work...