Code 41 OBD1
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Junior User
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Code 41 OBD1
So long story short, truck tripped code 41.
1993 f250 w/ 7.5. 148,xxx miles
HEGO no code detected
or lean code detected.
My sensor wires looked fine when I crawled under there. is there a way to test the sensor before taking it off the truck? And replacing it if that’s not the problem?
My truck has terrrible mileage as in 1/2 tank per 60 highway 😬🤷♂️
Another thought would be a vacuum leak somewhere introducing unburnt oxygen into the line.
Another, nother thought would be a cylander not firing for some reason and releasing unburnt oxygen down the line? I tried to do the cylander balance test but I don’t have that option since it’s so old
No MAF, I don’t think so. there’s no input of oxygen on the front end.
All trouble shooting ideas welcome! Got a decent trip with truck maxed out with shingles next weekend and would like to get better mileage over the mountain if I can.
1993 f250 w/ 7.5. 148,xxx miles
HEGO no code detected
or lean code detected.
My sensor wires looked fine when I crawled under there. is there a way to test the sensor before taking it off the truck? And replacing it if that’s not the problem?
My truck has terrrible mileage as in 1/2 tank per 60 highway 😬🤷♂️
Another thought would be a vacuum leak somewhere introducing unburnt oxygen into the line.
Another, nother thought would be a cylander not firing for some reason and releasing unburnt oxygen down the line? I tried to do the cylander balance test but I don’t have that option since it’s so old
No MAF, I don’t think so. there’s no input of oxygen on the front end.
All trouble shooting ideas welcome! Got a decent trip with truck maxed out with shingles next weekend and would like to get better mileage over the mountain if I can.
Lead Driver
Joined: Jan 2019
Posts: 5,081
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From: N.W. Alabama
crack in exhaust manifold, happens on 460's a lot, besides, vacuum leaks.
supposedly you can-->Oxygen Sensor Information
supposedly you can-->Oxygen Sensor Information
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Thanks for the link 👍🏻👍🏻
I was thinking back to high to high school science class when I heard something about diffusion. There’s no “membrain” in our situation but the high pressure in the manifold & exhaust and the low pressure outside. How would oxygen get inside the exhaust?
So my solution would be to find the leak/crack upstream and seal it with tape/puddy etc. any downstream leaks don’t matter.
I was thinking back to high to high school science class when I heard something about diffusion. There’s no “membrain” in our situation but the high pressure in the manifold & exhaust and the low pressure outside. How would oxygen get inside the exhaust?
So my solution would be to find the leak/crack upstream and seal it with tape/puddy etc. any downstream leaks don’t matter.
Hotshot
Joined: Jun 2015
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That is a short term “Band - Aid” fix at the most. The real solution is to replace the broken manifold.
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crack in exhaust manifold, happens on 460's a lot, besides, vacuum leaks.
supposedly you can-->Oxygen Sensor Information
supposedly you can-->Oxygen Sensor Information
any idea where the exhaust cracks typically are on 460’s?
I smoke tested the exhaust and it leaked like sieve from the drivers header/Y pipe connection but nothing else Pre-o2 sensor.
Slathered puddy on that seam and waiting for it to dry. I’ll do a second test smoke tomorrow night. Just wondering if there’s any other typically rust holes or leaking areas.
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I need to replace pumps I think because I have a hard starting issue where it doesn’t maintain pressure after turning off.
Just replaced regulator 4 months ago. Pressure was at that time 25 at idle and 30 WOT.
Would an an issue with that be connected to a 41/ o2 CODE?
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FTE Legend
Joined: Jun 2006
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From: Ottawa, Ontario
Yeah that pressure is way low, there should be 32-35psi at idle with vacuum attached to the pressure regulator, and any time the throttle is blipped(not held) or the engine is under load(low vacuum) pressure should rise. With vacuum removed from the regulator you should have 39-45psi.
A common problem with dual tank trucks is fuel transfer between tanks due to faulty or stuck control valves in the FDM inside the tanks. If the inactive tank is full to begin with the active tank will overfill it and spill fuel on the ground as you drive, making the fuel consumption look horrific. If there is a smell of raw fuel immediately after parking this could be a problem, look at the bottom of the full filler neck on the unused tank to see if it is wet.
A common problem with dual tank trucks is fuel transfer between tanks due to faulty or stuck control valves in the FDM inside the tanks. If the inactive tank is full to begin with the active tank will overfill it and spill fuel on the ground as you drive, making the fuel consumption look horrific. If there is a smell of raw fuel immediately after parking this could be a problem, look at the bottom of the full filler neck on the unused tank to see if it is wet.
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Yeah that pressure is way low, there should be 32-35psi at idle with vacuum attached to the pressure regulator, and any time the throttle is blipped(not held) or the engine is under load(low vacuum) pressure should rise. With vacuum removed from the regulator you should have 39-45psi.
A common problem with dual tank trucks is fuel transfer between tanks due to faulty or stuck control valves in the FDM inside the tanks. If the inactive tank is full to begin with the active tank will overfill it and spill fuel on the ground as you drive, making the fuel consumption look horrific. If there is a smell of raw fuel immediately after parking this could be a problem, look at the bottom of the full filler neck on the unused tank to see if it is wet.
A common problem with dual tank trucks is fuel transfer between tanks due to faulty or stuck control valves in the FDM inside the tanks. If the inactive tank is full to begin with the active tank will overfill it and spill fuel on the ground as you drive, making the fuel consumption look horrific. If there is a smell of raw fuel immediately after parking this could be a problem, look at the bottom of the full filler neck on the unused tank to see if it is wet.
i should re-test it. I remember it being within spec when I tested it.
Is this connected to CEL #41?
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Good news everybody
ran over the mountain 85 miles fully loaded 9,000lbs and had no check engine lights pop on.
Forgot to bring my code reader to see if there was pending but typically the CEL would pop on within 20 miles.
replaced the O2 sensor and files the gap between the header and Y-pipe.
Didnt have time to try one solution then the next if the light came on after the first fix. 👍🏻👍🏻
ran over the mountain 85 miles fully loaded 9,000lbs and had no check engine lights pop on.
Forgot to bring my code reader to see if there was pending but typically the CEL would pop on within 20 miles.
replaced the O2 sensor and files the gap between the header and Y-pipe.
Didnt have time to try one solution then the next if the light came on after the first fix. 👍🏻👍🏻
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