1996 Ford F150 OBD2 monitors reset at key off

1996 FORD F-150
149,000 MILES • 6 CYL • 2WD • MANUAL
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SNAPPERJ79
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  • 1 POST
I just bought a 96 f150. I need to get it emissions tested, but am having a problem. Every time I turn the key off for more than about a minute, the readiness flags reset. I have driven it a few times with my scan tool plugged in. If I drive it long enough, eventually most of the monitors will come on line, with the exception of catalyst and EGR monitors, but as soon as I shut it down it starts all over with every readiness flag but the misfire and fuel system flags not ready to test. The readiness flags that are reseting are the O2, O2 heater, secondary air, component monitor, EGR and catalyst. No driveablilty issues though. Thanks.
May 23, 2008 at 5:29 AM
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MASTERTECHTIM
  • ✓ASE Certified Mechanic
  • 4,750 POSTS
  • ASE Certified Mechanic
i have seen this problem a few times and have found that the keep alive memory wire to the computer to be bad. mostly i will just road test extensively and get most tests to pass then dont turn off the truck and get a sticker. if all powers and grounds are good then its inside the computer.
May 23, 2008 at 6:31 AM
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