Code 172 Mustang 1994. Can it be the egr ?

gdushkin

New Member
Nov 6, 2019
17
0
1
25
Massachusets
I have a 1994 5.0. I pulled the codes this morning and one of the codes was 172 running lean. How can I remedy that? I just checked vacuum leaks and fuel pressure everything seems to be working normally I don’t have an egr or an air injection pump. I had my egr plugged up by a plate with a gausket that I cut out of a piece of aluminum (it seems to seal just fine) . But I had the egr plug plugged by an eliminator plug from eBay could that be a problem or am I looking in the wrong spot.
 
  • Sponsors(?)


revhead347

Apparently my ex-husband made that mistake.
15 Year Member
Jun 14, 2004
8,792
1,456
214
41
Acworth, GA
It could be the problem. If the EGR is unplugged, it should throw a code for that as well.

Kurt
 

WhiteCobra95

5 Year Member
May 2, 2006
345
44
49
Are your O2 sensors in good shape? If the O2 sensors have gone bad and the voltage sticks low, it might be giving a lean feedback signal even though the system has adapted super rich. You might want to pull a spark plug and check the color to see if you're burning around stoich (tan) or if they're black.