hesitation, high cold idle and poor gas mileage

mattfurlani · 01-30-2007, 11:24 PM

i have the same problem what's a code 71?

sd88supra · 01-30-2007, 11:43 PM

code 71 is EGR malfunction. its not very specific, and i havent been able to figure out what exactly is wrong.

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.

sd88supra · 01-31-2007, 07:08 AM

Quote:

Originally Posted by mrnickleye

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.

I used to get good gas mileage even with the error code 71. It wasn't until recently that my cold idle went up (could outside temperature have anything to do with it?) The hesitation I've always had (around 2000 rpm), but it has gotten worse. Could it be that the EGR has worsened? In fact, the harder I accelerate the smoother it runs. No pinging. I'm gonna check my timing belt. I fact, I think I'm gonna go for a rebuild soon. I'm starting to show signs of a well worn engine.

01-30-2007, 11:24 PM	#1
mattfurlani 3" Exhaust Join Date: Aug 2006 Location: Rhode Island Posts: 63	i have the same problem what's a code 71? __________________ Its broke, it could be anything, and cost of repairs will greatly exceed the value of the car

01-31-2007, 04:32 AM	#3
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.

01-30-2007, 11:43 PM	#2
sd88supra 3" Exhaust Join Date: Oct 2005 Location: San Diego, Ca Posts: 190	code 71 is EGR malfunction. its not very specific, and i havent been able to figure out what exactly is wrong.