91 Ranger check engine light

[Electric_mouse]

Light comes on soon after running. No check engine light when first started but will come on after driving a distance.

Placed jump to read codes. I get a bunch and trying to understand what they are.

KOEO:
1,1,1,1,1,3,3,4,1,3,3,4,1
Stops after the last 1.
How would you experts break them down? I find them difficult to break into segments.


TIA

[Mustang_Driver]

https://www.therangerstation.com/tec...gitcodes.shtml




not sure if it helps

[ctesla]

mouse,
Mustang_Driver posted great link for your specific codes..
it did not if like GM, Ford flashes their 'system OK'; or start and end
of codes once or twice..
so your codes could be either:
11/11/33/41/11
or
11/13/34/11
hard to tell, as you say you had eng.off,
but both 34 and 41 say eng. running..
either way;
first you might check grounds; then run a tank of premium (or real good throttle body/
injection cleaner thru),
inspect EGR (since this is one of most common failures of early obd/emissions), since
it bolts directly to manifold (heat and carbon build up); so it might just need cleaning, not replacing (since i know prices for auto components in Canada are more extreme than in US).. purchase the gasket ($4?) and pull egr and clean component and where it bolts to engine of carbon build up and residue with toothbrush and carb clean or brake clean..
or- even prior to pulling, could try 'rapping' on it with wooden handle of tool and see if internal build up breaks free w/o removing from engine..

you didn't mention miles on rig, or if there was any driveability issues, or worsened idling, or major drop in mpg or previous maintenance prior to engine light; so this is just a suggestion(s) w/o more info/data..
hope this helps..

[Electric_mouse]

Thanks for the replies.
This vehicle has about 165k
It runs fine with no noticeable change in gas mileage but does idle a little rough when well warmed up as on return from a trip.



Pulled neg at battery to reset codes a few days ago and recorded the codes again today. Is it permissible to post the video here? Concerned about size limit.

[Stealthee]

You'll have to upload the video to YouTube or another host. The size limits for uploads here will make it not doable.

[Electric_mouse]

Just installed. Maybe this will work?

https://ln4.sync.com/dl/6b013aff0/36...7aujk-b6yp9zdt

[Electric_mouse]

Pulled the EGR valve. It seemed to be stuck because it had some resistance and made a “pop” sound when pressed with a screw driver. After that it moved freely and the potentiometer had good readings. Reinstalled and now the check engine light is cleared.
Not a fun job.