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Exhaust Code 31

  • Thread starter Thread starter fredfifty
  • Start date Start date Nov 25, 2017

fredfifty

5 Year Member
Nov 23, 2011
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59
SF Bay Area
Nov 25, 2017
#1
  • Nov 25, 2017
  • #1
driving around today for awhile, came home and CEL starts flashing...checked codes, its a 31 (and 67 due to NSS-thats another issue). Looked up the code via a web search, its a EGR/VPS issue apparently. Checked my VPS and sure enough there was something wrong..it wasn't seated properly on the EGR because the 3 mounting bolts were not tightened down all the way. Tightened them up, disconnected the battery, no more code 31. By the way the EGR and VPS are motorcraft and are new (few hundred miles on them) and them bitches aren't cheap sheesh.

so how does the bolts come loose? engine vibrations or? I know I tightened them fairly good when I installed them initially...atleast I thought I did.

I'm just glad this was an easy fix...
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,252
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Massachusetts
Nov 26, 2017
#2
  • Nov 26, 2017
  • #2
I thought the oem nuts used to secure it were the nylon insert type nuts to prevent loosening? Is this what you have?
 

fredfifty

5 Year Member
Nov 23, 2011
318
57
59
SF Bay Area
Nov 26, 2017
#3
  • Nov 26, 2017
  • #3
Yes nylon locking nut atleast thats what they look like
 

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Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,252
17,937
224
Massachusetts
Nov 26, 2017
#4
  • Nov 26, 2017
  • #4
Very odd. Those should back oyt
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,916
10,565
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polk county florida
Nov 26, 2017
#5
  • Nov 26, 2017
  • #5
Throw a dab of lock lite on 'em
 

jrichker

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Mar 10, 2000
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Dublin GA
Nov 27, 2017
#6
  • Nov 27, 2017
  • #6
Nylock inserts are only good up to 250° F. Above that the nylon insert tends to soften and loses its ability to insure that the nuts stay tight. Some of the Chinese manufactured hardware that is so common these days may have inserts that aren't even heat resistant to 250° F.

Google all metal self locking nuts to find a supplier near you. The size is either 8-32 or 10-32.
 
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