hesitation, high cold idle and poor gas mileage

mrnickleye · 01-31-2007, 04:32 AM

Well, if the EGR is stuck open a tiny bit, your idle can increase; cause cylinder misfires (lowered MPG); and can give you some running troubles.

The EGR passages on the 7m usually will plug up with miles, and then you don't get any EGR gasses thru. This problem is usually not detected (nor cause troubles)until you have to go in for an emissions test. It causes high NOx readings.

The main running trouble this plugged or inop EGR condition can cause is pinging under hard acceleration. This is due to extremely high combustion temps, which lowering it is why the EGR is there.

01-31-2007, 04:32 AM	#4
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	Well, if the EGR is stuck open a tiny bit, your idle can increase; cause cylinder misfires (lowered MPG); and can give you some running troubles. The EGR passages on the 7m usually will plug up with miles, and then you don't get any EGR gasses thru. This problem is usually not detected (nor cause troubles)until you have to go in for an emissions test. It causes high NOx readings. The main running trouble this plugged or inop EGR condition can cause is pinging under hard acceleration. This is due to extremely high combustion temps, which lowering it is why the EGR is there. __________________ Had a Red 1989 N/A. Automatic. Sports Pkg. w/wing. TEMS, and some nice MODS. Sold to a friend 10/08/08. Last edited by mrnickleye; 01-31-2007 at 04:35 AM.