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

car runs lean...

  • Thread starter Thread starter 90mustangfan
  • Start date Start date Oct 19, 2005

90mustangfan

New Member
Oct 18, 2005
93
0
0
So cal
Oct 19, 2005
#1
  • Oct 19, 2005
  • #1
Heres the situation.. Ive been getting codes 41 and 91 for KOEO and KOER....
KOEOR: 41-No hego switching detected running lean (right side)
91-hego sensor cuircuit indicated system lean (left side)
Contienus memory: 41-Hego sensor indicateds system running lean (right side)
91 no Hego switching dected always Lean(left side)
I just replaced my O2 sensors, i checked the wiring all the way to the computer, thats good.It says the car is running lean, I replaced ALL vaccum hoses and hooked them up correctly, it has good vaccum 15hg at idle...What puzzles me is that the car runs great....Any ideas on whats causing it to run lean or why I keep getting these codes...I need to get the check engine light to stop coming on and I need to take it to a smog shop so I can register it...
 
You must log in or register to reply here.

Similar threads

M
Progress Thread 1993 Ford Mustang 5.0 convertible stock manual - ODB Codes shows running lean
  • mcalvo
  • Feb 11, 2025
  • Fox 5.0 Mustang Tech
  • 2
Replies
20
Views
1K
Fox 5.0 Mustang Tech Feb 22, 2025
AeroCoupe
Engine 1990 LX 5.0L EFI Mustang Fuel Management Problems - HELP!
  • 5.0LXStanger
  • May 25, 2025
  • Fox 5.0 Mustang Tech
  • 2 3
Replies
45
Views
2K
Fox 5.0 Mustang Tech Jul 11, 2025
5.0LXStanger
Engine 87 NA - Tune or no Tune needed?
  • R82148V
  • Sep 17, 2025
  • Fox 5.0 Mustang Tech
Replies
8
Views
316
Fox 5.0 Mustang Tech Sep 17, 2025
R82148V
2
Running very very rich
  • 2esoteric
  • Oct 31, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
311
Fox 5.0 Mustang Tech Oct 31, 2025
Noobz347
S
Fuel ‘88 GT Runs Rich Cold — Fixes Itself When I Unplug Sensors (ECT, MAF, O2, etc.)
  • Sufarry
  • Nov 6, 2025
  • Fox 5.0 Mustang Tech
Replies
12
Views
740
Fox 5.0 Mustang Tech Nov 9, 2025
Mustang5L5
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?