94 Explorer, pulled codes, fixed, new codes

[paulha]

About three weeks ago I acquired this 94 Explorer XLT. About two weeks and 4 days ago I joined this forum and have been reading ever since. It was in need of lots and lots of care. Have replaced door panes, bushings in 2 window motors, repaired three door switches and much more. I ran the codes with my EZ Scan 3000 and got the following:
KOEO:
335
539
544
Memory:
157
172
176
KOER:
326
538
536
126
I then replaced the DPFE with one from the salvage, cleaned the MAF sensor and cleared the codes.
Warmed it up and took codes again. this time:
KOEO:
341
Memory:
111
KOER:
172
536
Where do I go from here? Also I can't find what defines "1st Generation or 2nd or 3rd? Is there someplace that has a list of solutions for the error codes or is it just solved from experience and these fantastic forums. Thank you in advance for any and all help. I am so glad I found this place.
Paul

 

[natenkiki2004]

341 is a octane adjust shorting bar removed, you can ignore this but it basically removes 3 degrees of advance to prevent pinging.
111 is system pass, this is good.
172 is O2 sensor lean.
536 is because you didn't tap the brake when doing the KOER test.

Really, there's not much to do now. 172 is cause for concern but it can be a number of things. Might be a vacuum leak or a dead O2 sensor. Clear the codes again and drive it for a week then revisit.

I made a video on how to perform the tests, it shows you when to tap the brake and give the goose:

 

[paulha]

341 is a octane adjust shorting bar removed, you can ignore this but it basically removes 3 degrees of advance to prevent pinging.
111 is system pass, this is good.
172 is O2 sensor lean.
536 is because you didn't tap the brake when doing the KOER test.

Really, there's not much to do now. 172 is cause for concern but it can be a number of things. Might be a vacuum leak or a dead O2 sensor. Clear the codes again and drive it for a week then revisit.

I made a video on how to perform the tests, it shows you when to tap the brake and give the goose:

Thanks for the fast reply. I will look for the O2 sensor and check for vacuum leaks, also I did tap the brakes when the scanner told me to, 3 different times I think. I will clear and drive for a week then retest. Thanks again.

 

[natenkiki2004]

In that case, it's possible your brake switch doesn't work. Do you have cruise control? Does it work for that?

 

[paulha]

In that case, it's possible your brake switch doesn't work. Do you have cruise control? Does it work for that?

I have cruise control but it doesn't work? I haven't tried to work on it yet, also my ABS light is on sometimes.

 

[natenkiki2004]

Well, that just might be a piece of the pie. Maybe your brake switch is shorted or messed up somehow. Try the test manually as I showed in the video, without your code reader and see if you get the same error back. If so, that's where I'd look. There's something about the cruise and brake switch going through the 3rd high mount brake light, maybe one of those bulbs is burned out?

 

[paulha]

Well, that just might be a piece of the pie. Maybe your brake switch is shorted or messed up somehow. Try the test manually as I showed in the video, without your code reader and see if you get the same error back. If so, that's where I'd look. There's something about the cruise and brake switch going through the 3rd high mount brake light, maybe one of those bulbs is burned out?

Ok so both of the bulbs on the high mount brake light were bad and I replaced them so as soon as I can I will see if the Cruise works. Thanks again. Also what denotes the various "Generations"?

 

[natenkiki2004]

Also what denotes the various "Generations"?

Pretty much all cars have it. A certain model/style will be produced for a couple years and then they move on and redesign the look. Wikipedia gives you a good idea, it's easy to spot the early year generations for body styles:
https://en.wikipedia.org/wiki/Ford_Explorer#First_generation_.281991.E2.80.931994.29

 

[paulha]

Pretty much all cars have it. A certain model/style will be produced for a couple years and then they move on and redesign the look. Wikipedia gives you a good idea, it's easy to spot the early year generations for body styles:
https://en.wikipedia.org/wiki/Ford_Explorer#First_generation_.281991.E2.80.931994.29

Thanks for the info, appreciate it. Ok so I tested the fuel sending unit as per another thread, Disconnected the sending unit at the tank, turned on ign, gauge read full, grounded the yellow/white wire, gauge still read full?
Just pulled codes again:
KOEO: 341
KOER: 536
Memory: 542
This time I pulled the DCL codes, interesting info but don't know what to do with that info? Since I unplugged the connector to the sending unit/fuel pump, is that the reason for the 542 code? If the brake lights are working how is the BOO switch bad? On to trying to fix fuel gauge. Thank you so much for all the response.
Paul

 

[92exp4x4]

I believe 542 is the fuel pump circuit open, probably caused by having the key on with the pump unplugged. 341 is the octane shorting bar, as previously mentioned. Most of the time when this is removed a previous owner had pinging problems. These engines are known for this and the most common cure is resealing the upper and lower intake. Not a bad job but a little scary for the first time home mechanic. You may consider doing this should you put the shorting bar back in the harness. You might be amazed at how much better it will run and it will get better fuel economy. Make sure your intake tube is good too. They are bad about cracking near the throttle body on the bottom side. Any un-metered air can cause pinging, the computer uses the MAF for this purpose, so any leaks past the air box can throw it out of whack.

Is your gauge jacked up? There is a module between the sender and the gauge called the anti slosh module. Its a circuit board in the gauge cluster that signals the needle and keeps it from sweeping wildly as you drive. This could be the issue in your gauge if your sender is good. I'm not really sure how to test it other than swap it out. I haven't gotten to that point yet. ( I just fill up every 200 miles) I have two trucks where the fuel gauge is inoperable, both have new sending units.

 

[paulha]

I believe 542 is the fuel pump circuit open, probably caused by having the key on with the pump unplugged. 341 is the octane shorting bar, as previously mentioned. Most of the time when this is removed a previous owner had pinging problems. These engines are known for this and the most common cure is resealing the upper and lower intake. Not a bad job but a little scary for the first time home mechanic. You may consider doing this should you put the shorting bar back in the harness. You might be amazed at how much better it will run and it will get better fuel economy. Make sure your intake tube is good too. They are bad about cracking near the throttle body on the bottom side. Any un-metered air can cause pinging, the computer uses the MAF for this purpose, so any leaks past the air box can throw it out of whack.

Is your gauge jacked up? There is a module between the sender and the gauge called the anti slosh module. Its a circuit board in the gauge cluster that signals the needle and keeps it from sweeping wildly as you drive. This could be the issue in your gauge if your sender is good. I'm not really sure how to test it other than swap it out. I haven't gotten to that point yet. ( I just fill up every 200 miles) I have two trucks where the fuel gauge is inoperable, both have new sending units.

Not to sure about sealing the upper and lower intake or where the shorting bar is/goes. I did replace the fule gauge with one from the salvage and so I'm pretty sure it works now, and replaced the anti-slosh module also, could be the ant-slosh module I put in was bad, still have the old one, but is a pain to get too. May have to try that next. I may try to check the wiring at the fire wall also to make sure there aren't any shorts between there and the plug at the tank? The beat goes on. Thanks again, anyone else run into this?

 

[92exp4x4]

I remember it being referenced in some of my diagrams. I will try to find a picture of where the shorting bar is located. I cannot remember where it is.

 

[92exp4x4]

It kind of resembles a fuse and plugs into the harness like one.

 

[FR-425]

Octane shorting bar is on the harness at the OBD test port.

 

[paulha]

Octane shorting bar is on the harness at the OBD test port.

Thanks I will look for it, still trying to figure out what is involved in sealing the upper and lower intake.

Are there any pics anywhere? Also just checked my mileage and I am getting 10.5, that sure seems awful low to me? Is that normal for this engine?

 

[92exp4x4]

Thanks I will look for it, still trying to figure out what is involved in sealing the upper and lower intake.

Are there any pics anywhere? Also just checked my mileage and I am getting 10.5, that sure seems awful low to me? Is that normal for this engine?

I typically get between 15-22 from any one of my trucks.

 

[92exp4x4]

Have you searched the forum for the intake reseal? I would imagine someone has done a write up on it. You would be removing the top end of the engine less the heads.

 

[natenkiki2004]

https://dl.dropboxusercontent.com/u/464376/vehicles/1991 Explorer/40LIntakeGasketReplacement.pdf

 

[Turdle]

The rectangle shaped gray thing plugged into the harness is the octane shorting bar. Hope this helps!

 

[paulha]

I found the plug for the Octane bar, can't find the shorting bar and none of the parts stores carry them so I guess I will try the salvage for that. How can I tell if the intake manifold is leaking(hoping for a miracle here)? The file is really good natenkiki2004 and easy to follow, but does look a little intimidating to me. Have to replace the drivers electric window regulator, any advice is sure appreciated here, especially concerning not having the spring take and arm off!!! And are a lot of the parts for 91-95's interchangeable? Have made some real progress on this so far thanks to this forum, I really appreciate your advice and willingness to share your experience so freely. I checked the resistance on the sending unit for the fuel gauge and got 22.5 with over half a tank, so I'm guessing the sending unit is bad. Now I need to get my mileage better than 10mpg! O;ne thing at a time, right?
Thanks so much.