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Engine O2 sensor ?

  • Thread starter Thread starter tigercity45
  • Start date Start date Jun 8, 2022

tigercity45

New Member
Jun 8, 2022
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Jun 8, 2022
#1
  • Jun 8, 2022
  • #1
Having some issues with my 87 fox. Idle is off and when driving it back fires when you let go of the gas and also won’t let me go past 3k rpm. Just stutters. But got a reader and all codes showed up at my O2 sensor and a fuel pump secondary circuit fault. Not sure if this is something that can cause these problems. What do y’all think
 

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KRUISR

10 Year Member
Apr 16, 2015
1,791
884
143
Jun 8, 2022
#2
  • Jun 8, 2022
  • #2
An O2 sensor that works intermittently would definitely cause drivability issues.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
27,826
10,507
203
polk county florida
Jun 8, 2022
#3
  • Jun 8, 2022
  • #3
Vacuum leak or low fuel pressure
you ever check fuel pressure?
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,154
17,844
224
Massachusetts
Jun 8, 2022
#4
  • Jun 8, 2022
  • #4
Is this a mass air swap car? I’m assuming yes because the VSS code is 1989+ only.

If so, was the fuel pump monitor and VSS wiring connected to the ECU during the conversion? If not, that explains the code 29 and 96.

41/91 can be triggered by faults with the air injection system and clogs in the crossover tube. What’s the status of the air injection system? Hooked up? Bypassed? Partially deleted? Completely removed including crossover tube?
 
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