DTC 41
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DTC 41
My truck threw a cel the other day as I was on my way to get the emissions test done. I didn’t have time to run the scan that day, but when I did run the codes yesterday the cel had disappeared. I checked for stored codes and found none. I ran the KOER test and it gave me DTC 41 (HO2S sensor low voltage/system lean). My truck failed on high HC (too much fuel), so I’m guessing the O2 sensor has something to do with this? Does any one have experience with this code and how to fix it?
1993 F250 4x4 5spd 7.5
1993 F250 4x4 5spd 7.5
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Well bummer on the failing test. I thought when you said the light went back out you were going to report smooth sailing after that!
Don't really know about that code, but aside from an actual wiring issue, couldn't a worn out tired sensor cause it as well? Not that I recommend throwing expensive parts at a problem, but curious which way it turns out.
Also thought we had three-digit codes in '93? Do we have both, or was this a transition year and it depends on what model?
Good luck.
Paul
Don't really know about that code, but aside from an actual wiring issue, couldn't a worn out tired sensor cause it as well? Not that I recommend throwing expensive parts at a problem, but curious which way it turns out.
Also thought we had three-digit codes in '93? Do we have both, or was this a transition year and it depends on what model?
Good luck.
Paul
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If the Check Engine Light (CEL) was illuminated during operation there should have been a Stored Code set.
Code 41 indicates the O2 sensor feedback is telling the computer the air/fuel ratio is lean therefore the computer will dump in more fuel to compensate. Any exhaust leak upstream of the O2 sensor can trigger false lean codes. Any vacuum leaks in the intake can also trigger lean codes.
As an O2 sensor ages it typically starts to slow down on the switching which can trigger a lean code. How old is the O2 sensor?
If the O2 sensor is covered in dirt/grease/grime that can also trigger false lean codes.
Code 41 indicates the O2 sensor feedback is telling the computer the air/fuel ratio is lean therefore the computer will dump in more fuel to compensate. Any exhaust leak upstream of the O2 sensor can trigger false lean codes. Any vacuum leaks in the intake can also trigger lean codes.
As an O2 sensor ages it typically starts to slow down on the switching which can trigger a lean code. How old is the O2 sensor?
If the O2 sensor is covered in dirt/grease/grime that can also trigger false lean codes.
Fleet Owner
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From: Kentucky
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RLA is correct. My 1993 gives two digit codes. Will I only have one o2 sensor or is there one on each side? I don't know the age of my sensor(s) I’ll have to ask the PO. I think I’ve got an exhaust leak where my manifold meets my exhaust pipe on the drivers side. Is there a gasket there or will I need to consult a muffler shop?
Fleet Owner
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Your truck has one O2 sensor located at the cross-over of the H-pipe. I recall it is located on the top of the small cross-over pipe so it may be hard to see.
That may be a good idea.
There is no gasket in between the exhaust manifold and pipe. It's a ball and socket connection. Even a small leak can trigger a false lean code. Fix the leak your Code 41 will most likely disappear.
That may be a good idea.
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Thanks RLA. You boys on this forum are some good folk. I suppose I’ll have to figure out exactly where my leak is, but if it’s just a hole, can I get it plugged by a muffler shop? My truck is straight piped from the cat so I’ve been meaning to throw a muffler on there any how. Would be a good time to get it all done.
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Fleet Owner
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If it is a hole in the head/H-pipe it can most likely be welded shut. If the manifold is cracked that is another story.
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Very prone to cracking. The stock manifold versus headers argument has valid points on both sides. Good quality headers are priced like gold. Factory style manifolds from the aftermarket have spotty quality even on a good day. Ford no longer makes to the best of my knowledge.
Once you start dismantling the manifolds you will most likely break the EGR tube. Finding one is next to impossible too. It snowballs quickly.
Once you start dismantling the manifolds you will most likely break the EGR tube. Finding one is next to impossible too. It snowballs quickly.
Fleet Owner
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From: Kentucky
Many folks swear by Gale Banks TorqueTubes Exhaust Headers and Y-pipe
As stated previously they are priced like gold. There are others out there but this is not an area where you want to go cheap.
As stated previously they are priced like gold. There are others out there but this is not an area where you want to go cheap.
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