Code 41
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Code 41
1993 f250 7.5/e4od 4x4. Last night i cranked truck and it idled 3-4 min and when i pulled out onto hiway it cut out for a split second. One mile down road bout 45mph it cut out same way. Once again it did and i was in the throttle and cel came on for 2-3sec then back off. I didn’t notice if i loss power on gauges but it seems to have lost ignition. Seems like most of my issues are always when engine has warmed up. This past Saturday i had a code 41 which i think has to do with o2sensor or egr. I replaced o2sensor back in 2020. Any ideas?
Fleet Owner
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From: Kentucky
Are you 100% sure you got two digit codes? I would expect a 1993 model year truck with an E4OD would be three digit.
If it is a true two digit code then the definition for Code 41 (Continuos Memory): HEGO sensor circuit indicates system lean. Code 41 KOER: No HEGO switching detected always lean
That does not indicate the O2 sensor is bad.
If it is a true two digit code then the definition for Code 41 (Continuos Memory): HEGO sensor circuit indicates system lean. Code 41 KOER: No HEGO switching detected always lean
That does not indicate the O2 sensor is bad.
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Are you 100% sure you got two digit codes? I would expect a 1993 model year truck with an E4OD would be three digit.
If it is a true two digit code then the definition for Code 41 (Continuos Memory): HEGO sensor circuit indicates system lean. Code 41 KOER: No HEGO switching detected always lean
That does not indicate the O2 sensor is bad.
If it is a true two digit code then the definition for Code 41 (Continuos Memory): HEGO sensor circuit indicates system lean. Code 41 KOER: No HEGO switching detected always lean
That does not indicate the O2 sensor is bad.
Cross-Country
Joined: Oct 2021
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My truck has this exact code. So it seems they do give two digit codes. Mine was also read with a code reader, not by counting flashes. I suppose it's possible both of our trucks have "something amiss", but I don't think so.
Let me know if you find the cause. I had vacuum leaks and it was need of a tune up, so now it runs a LOT better. I'm thinking about clearing the codes to see if it comes back. Vacuum or exhaust leaks could cause the sensor to read constant lean. Are you using a lot of fuel? Another possibility is that your truck is actually running lean enough that the sensor appears to be stuck lean to the computer. It may be a good idea to check fuel pressure and use an automotive stethoscope to listen to the injectors to make sure they're all working. Good luck!
Let me know if you find the cause. I had vacuum leaks and it was need of a tune up, so now it runs a LOT better. I'm thinking about clearing the codes to see if it comes back. Vacuum or exhaust leaks could cause the sensor to read constant lean. Are you using a lot of fuel? Another possibility is that your truck is actually running lean enough that the sensor appears to be stuck lean to the computer. It may be a good idea to check fuel pressure and use an automotive stethoscope to listen to the injectors to make sure they're all working. Good luck!
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Fleet Owner
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From: Kentucky
I agree, but even with an older PCM installed Code 41 indicates the engine is running lean. Given your symptoms I suggest you pull out the computer (PCM) then open it up to look for signs of leaking capacitors. While you have the box in your hands note the numbers on it.
If the inside of the computer looks good then I suggest to check the fuel pressure. You can rent a tester at most parts stores. Should be ~ 30-32 PSI at idle. Removing the vacuum hose the fuel pressure regulator the pressure should rise to ~40-45 PSI. Check the pressure under load as well. It should rise to that same 40-45 PSI as the load increases. I do this test by taping the pressure gauge to the windshield then carefully drive the truck and flooring the throttle a few times.
FWIW...my old 1992 F350 w/5.8L engine and E4OD displayed three digit codes. Yes I verified it had the correct PCM. Seems odd Ford was still using two digit codes in 1993.
If the inside of the computer looks good then I suggest to check the fuel pressure. You can rent a tester at most parts stores. Should be ~ 30-32 PSI at idle. Removing the vacuum hose the fuel pressure regulator the pressure should rise to ~40-45 PSI. Check the pressure under load as well. It should rise to that same 40-45 PSI as the load increases. I do this test by taping the pressure gauge to the windshield then carefully drive the truck and flooring the throttle a few times.
FWIW...my old 1992 F350 w/5.8L engine and E4OD displayed three digit codes. Yes I verified it had the correct PCM. Seems odd Ford was still using two digit codes in 1993.
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Cross-Country
Joined: Oct 2021
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Maybe they used an older PCM on the 7.5L? That's what we both have. I'll have to see if I can get the numbers off mine later
*edited because I typed ECM instead of PCM. Doh!
*edited because I typed ECM instead of PCM. Doh!
Last edited by coder#; Oct 14, 2021 at 02:34 PM.
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Replaced PCM back in 2017. Doesn’t rule out the pcm but….Im gonna do some wire testing and see where that goes.
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My truck has this exact code. So it seems they do give two digit codes. Mine was also read with a code reader, not by counting flashes. I suppose it's possible both of our trucks have "something amiss", but I don't think so.
Let me know if you find the cause. I had vacuum leaks and it was need of a tune up, so now it runs a LOT better. I'm thinking about clearing the codes to see if it comes back. Vacuum or exhaust leaks could cause the sensor to read constant lean. Are you using a lot of fuel? Another possibility is that your truck is actually running lean enough that the sensor appears to be stuck lean to the computer. It may be a good idea to check fuel pressure and use an automotive stethoscope to listen to the injectors to make sure they're all working. Good luck!
Let me know if you find the cause. I had vacuum leaks and it was need of a tune up, so now it runs a LOT better. I'm thinking about clearing the codes to see if it comes back. Vacuum or exhaust leaks could cause the sensor to read constant lean. Are you using a lot of fuel? Another possibility is that your truck is actually running lean enough that the sensor appears to be stuck lean to the computer. It may be a good idea to check fuel pressure and use an automotive stethoscope to listen to the injectors to make sure they're all working. Good luck!
Cross-Country
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Mine was getting maybe 4 mpg when I first bought it. Fixed some vac lines and that alone got me up to around 8-10mpg. It's hard to calculate since I have a fuel vent tube plugged so I have to fight to fuel it up. lol. Hard to tell when it's really "full" when the stupid thing shuts off the pump every couple of seconds. Since then, I've done tune up stuff and it's running a LOT better. Just did the cap and rotor today and it's like a brand new engine. Never thought that big V8 could run so smoooooth.
I kinda wonder if your coil is on it's way out. I had an expedition that had a faulty coil that would buck HARD but randomly. Took some time to track that one down.
Good luck man. Hope you figure it out
I kinda wonder if your coil is on it's way out. I had an expedition that had a faulty coil that would buck HARD but randomly. Took some time to track that one down.
Good luck man. Hope you figure it out
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Mine was getting maybe 4 mpg when I first bought it. Fixed some vac lines and that alone got me up to around 8-10mpg. It's hard to calculate since I have a fuel vent tube plugged so I have to fight to fuel it up. lol. Hard to tell when it's really "full" when the stupid thing shuts off the pump every couple of seconds. Since then, I've done tune up stuff and it's running a LOT better. Just did the cap and rotor today and it's like a brand new engine. Never thought that big V8 could run so smoooooth.
I kinda wonder if your coil is on it's way out. I had an expedition that had a faulty coil that would buck HARD but randomly. Took some time to track that one down.
Good luck man. Hope you figure it out
I kinda wonder if your coil is on it's way out. I had an expedition that had a faulty coil that would buck HARD but randomly. Took some time to track that one down.
Good luck man. Hope you figure it out
Fleet Owner
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From: Kentucky
It is not a hard and fast rule. The 7.5L trucks seems to be the oddball versions. They got the remote mount ICM in the late 80's, but the small block/I6 did not get them until 1992. Because of the ambiguity I always question someone posting two digit codes on ~1992 and later trucks to ensure they are really getting two digit codes when the computer is actually sending out three digit.
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