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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

really bad feul mileage?

  • Thread starter Thread starter red-fox
  • Start date Start date Jun 7, 2011
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Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,244
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Massachusetts
Jun 10, 2011
#21
  • Jun 10, 2011
  • #21
red-fox said:
but usually if theres no light theres no code.
Click to expand...

That's not true with OBD-1/EEC-IV

Of the 99 or so possible codes, only 13 trip the light.
 

red-fox

Active Member
Nov 1, 2010
86
2
28
Manitoba
Jun 10, 2011
#22
  • Jun 10, 2011
  • #22
ok, I did see the light flash but I wasn't really paying attention to it so I'm not sure if it flashed twice but it did flash.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,244
17,924
224
Massachusetts
Jun 10, 2011
#23
  • Jun 10, 2011
  • #23
red-fox said:
operating temp engine off but key was on
Click to expand...

You need to do the codes with the key off, and then a second time with the key on. That will test the engine running codes and things like EGR, and o2 sensors.

These cars aren't like newer OBD2 cars. There are actually 3 different sets of codes to read. Key on, engine off, continuous memory, and then key on, engine running codes.

You need to get three 11 codes to be considered a pass
 

red-fox

Active Member
Nov 1, 2010
86
2
28
Manitoba
Jun 11, 2011
#24
  • Jun 11, 2011
  • #24
Ok, weekends pretty busy but I'll do some more scanning when I have time with key on and off and will watch for the code 11. thanks for all the help!
 
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