Please Help Me What Does This Mean.....2011 Odyssey EX-L....Big Or Small Repair...Easy Fix???
Thanks In Advance
Thanks In Advance
Check Engine Light P0171 Code
Petey38
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Did the light ever come back on? Here is something you might want to check.
My 2012 EX-L with about 148k on it just threw a P0171 and a P0174. The check engine line came on while my wife was driving it last week, but by the time she got home and I could check it, the light was off. I scanned it anyway, and the codes are still there as current, so I'm not sure why the light went off. Light is still off today a week later, and codes are still present.
Anyway, I just changed the air filter about a month ago so I figured I'd check and see if didn't close the airbox all the way or left something loose and noticed this big crack in the intake tube:
I ordered a new intake tube and it will be here tomorrow, and expect the codes to clear themselves after that.
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That will definitely cause lean codes if there is a mass airflow sensor before that tube. Those tubes are common failures.
Lean codes are two trip detection so it takes two consecutive failures to turn on the light even though the code may be pending.
Additionally, 2012 and newer cars will store the code for 50 or more drive cycles even after you clear the code.
The best thing to do is look at your fuel trims before and after the repair to know if you've fixed the problem.
Lean codes are two trip detection so it takes two consecutive failures to turn on the light even though the code may be pending.
Additionally, 2012 and newer cars will store the code for 50 or more drive cycles even after you clear the code.
The best thing to do is look at your fuel trims before and after the repair to know if you've fixed the problem.
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All these scan tools can lie. Don't take everything it says as literal. Take a look at the fuel trims before replacement then after replacement.
There is a lot at play here. Vacuum leaks are worse at idle than at higher rpm. However, a crack like that can sometimes seal itself depending on engine rpm and load. The tube will flex as the engine is put under load and the crack will open and close. You may see variations in fuel trims and the light may come and go.
There is a lot at play here. Vacuum leaks are worse at idle than at higher rpm. However, a crack like that can sometimes seal itself depending on engine rpm and load. The tube will flex as the engine is put under load and the crack will open and close. You may see variations in fuel trims and the light may come and go.
part came today, and I just put it in. I looked at the fuel trims with it idling in the driveway before and after, not sure if you need to drive it around at all to get more accurate numbers, but this is what I see. The short term fuel trim numbers went from reading +6 to +14% before putting in the new hose (left) to -1 to -5 after (right):
![154111]( "154111")
![154112]( "154112")
Does that mean it's running slightly rich now? What are normal numbers to see here?
The codes are still there, I'm going to wait and see if they clear after a few drive cycles, if not I'll clear them and check they don't come back.
Does that mean it's running slightly rich now? What are normal numbers to see here?
The codes are still there, I'm going to wait and see if they clear after a few drive cycles, if not I'll clear them and check they don't come back.
Looks like the short term trim is still moving the long term trim (they have opposite signs). If it were me, I'd clear the codes and start everything 'fresh' after a change/fix like that.
-Charlie
-Charlie
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I agree with the above. It looks like a fix to me. Short term fuel trims will move the other direction on order to bring the long terms back toward zero. You can clear the codes or leave it. If the light stays out then it's fixed. It takes long term fuel trims above 20% to set a code.
Thanks guys, I cleared the codes and long term trims are reset to 0 now and short term trims showing in the 0-3% range.
I still find it weird that the light was already out, but the current fault codes were still there. The CEL came on for only one day while my wife was driving it, but by the time she got home it was off. The codes were still there (a week later) showing as current up until I cleared them. I'm guessing that when the tube initially ripped, the long term trims spiked up enough to trigger the code and CEL, but since it was a small enough leak the computer was able to adjust and it turned the light out.. Either that or there was another code that triggered the light, yet cleared itself before I was able to scan it. I've just never seen current fault codes trigger the light then the light goes out without the codes going to pending or historical.
![154119]( "154119")
I still find it weird that the light was already out, but the current fault codes were still there. The CEL came on for only one day while my wife was driving it, but by the time she got home it was off. The codes were still there (a week later) showing as current up until I cleared them. I'm guessing that when the tube initially ripped, the long term trims spiked up enough to trigger the code and CEL, but since it was a small enough leak the computer was able to adjust and it turned the light out.. Either that or there was another code that triggered the light, yet cleared itself before I was able to scan it. I've just never seen current fault codes trigger the light then the light goes out without the codes going to pending or historical.
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You're putting too much emphasis on the word "current." In my experience it means nothing. All these scan tools are made in China and you cannot trust everything you read on them. Some cars will have pending codes that show up under stored codes.
Most likely it was only bad enough to set the code at certain engine load conditions where the engine moved enough to open the Crack to wide enough to go above the threshold. It will set a code the first time it sees it but won't turn on the light until it sees it again. If in another key cycle or two it doesn't see it it will turn off the light but leave the code.
If you had the factory Honda scan tool you'd likely see everything under the right headings.
Lastly, on 2012 and newer cars even though you've cleared the codes they are still stored in a history that you cannot clear until the vehicle goes through some high number of successful drive cycles...something like 50 drive cycles. Some scan tools will see that and some won't. Again, witthh aftermarket scan tools you have to take the info with a grain of salt in many cases. They all can/will lie in many cases.
Most likely it was only bad enough to set the code at certain engine load conditions where the engine moved enough to open the Crack to wide enough to go above the threshold. It will set a code the first time it sees it but won't turn on the light until it sees it again. If in another key cycle or two it doesn't see it it will turn off the light but leave the code.
If you had the factory Honda scan tool you'd likely see everything under the right headings.
Lastly, on 2012 and newer cars even though you've cleared the codes they are still stored in a history that you cannot clear until the vehicle goes through some high number of successful drive cycles...something like 50 drive cycles. Some scan tools will see that and some won't. Again, witthh aftermarket scan tools you have to take the info with a grain of salt in many cases. They all can/will lie in many cases.
I'm using the Torque app and bluetooth dongle, and in my experience the status of the fault codes has always been accurate. It tells you whether the code is current, pending or historical. I guess it's possible that it can't tell the difference between current and pending for this car, but that would be strange since that is the standard way of storing the fault codes.
Here is what it looked like before I cleared the codes, and no check engine light on:
![154129]( "154129")
and now it shows no codes at all after clearing:
![154127]( "154127")
I know it can at least read historical codes, because when my evap canister got flooded (the only other time I needed to scan codes on this car), the code for that stuck around in historical for a while even after I replaced the canister and cleared the codes:
![154128]( "154128")
Here is what it looked like before I cleared the codes, and no check engine light on:
and now it shows no codes at all after clearing:
I know it can at least read historical codes, because when my evap canister got flooded (the only other time I needed to scan codes on this car), the code for that stuck around in historical for a while even after I replaced the canister and cleared the codes:
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Again, scan tools are great devices and give you valuable information but don't take them as 100% accurate for every detail. All the apps and scan tools use the same data from the car and many of them use the same pirated reverse engineered software to read the car's data. They don't always have the software correct. The only 100% trustworthy scan tool for a Honda is the HDS.
It's called two-trip detection. The following is right from the 2012 service manual, "Two Drive Cycle Detection Method: When an abnormality occurs in the signal from a sensor or from another control unit in the first drive cycle, the PCM stores a Pending DTC. The MIL does not come on at this time. If the failure continues in the second drive cycle, the PCM stores a Confirmed DTC and turns on the MIL." P0171 and P0174 are two drive cyelc codes. If the computer sees the code once it will put it in pending status and not turn on the light. It may stay in the "current" section since it did turn on the light at one time. If it sees it on the next drive cycle it will turn on the light. If the light was out then it had not seen it in at least two consecutive drive cycles. Generally, two trip detection codes will turn out the light if the PCM doesn't see the fault for three or more drive cycles or sometimes even just key cycles. With the intermittent nature of the failure (the crack in the boot) it's not surprising that it wouldn't see high fuel trims above the threshold for the code, all the time.
It's called two-trip detection. The following is right from the 2012 service manual, "Two Drive Cycle Detection Method: When an abnormality occurs in the signal from a sensor or from another control unit in the first drive cycle, the PCM stores a Pending DTC. The MIL does not come on at this time. If the failure continues in the second drive cycle, the PCM stores a Confirmed DTC and turns on the MIL." P0171 and P0174 are two drive cyelc codes. If the computer sees the code once it will put it in pending status and not turn on the light. It may stay in the "current" section since it did turn on the light at one time. If it sees it on the next drive cycle it will turn on the light. If the light was out then it had not seen it in at least two consecutive drive cycles. Generally, two trip detection codes will turn out the light if the PCM doesn't see the fault for three or more drive cycles or sometimes even just key cycles. With the intermittent nature of the failure (the crack in the boot) it's not surprising that it wouldn't see high fuel trims above the threshold for the code, all the time.
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Hello all. 2011 Ody EX-L. purchased Sept 2020 at one-owner 85,000 miles, now 106885 miles. Always use Top Tier gas. Timing belt, water pump, OEM plugs at 103000 miles. Recently after a 50 mile highway drive, started engine to return home, CEL appeared. Stayed on during the return trip. Next morning, on engine start, CEL was out. Checked code at O'Reillys, got P0171 (1/2) lean bank 1. Called my trusted mechanic to make appointment. He said first try fuel injector cleaner. Fill tank - drive awhile, see if CEL stays off. Thoughts?
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The "1/2" usually means that's 1 of 2 codes that are stored. Was P0174 also stored? It's important to know if it's lean on only one bank or both.
First thing I'd check is the big air intake tube between the air filter and the throttle body. Look on top and bottom for any splits in the rubber tube.
First thing I'd check is the big air intake tube between the air filter and the throttle body. Look on top and bottom for any splits in the rubber tube.
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Thank you. Big air intake tube split wide open, 1/16" wide, top half of circumference right at the connection to the intake. Terrible design. I came out of the plastics molding industry, and plastic was never meant to be applied like that with stress molded in, eventually splitting open!! Picking up Dorman 606-020. While at it, also air filter.
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It's supposed to be soft rubber, not hard plastic. Remember, it's 11 years old in a hot environment and has hardened over time.
I went with the OE one from Honda rather than the cheap Dorman one but if it fails again you can buy several for the cost of the Honda part.
I went with the OE one from Honda rather than the cheap Dorman one but if it fails again you can buy several for the cost of the Honda part.
Check your motor mounts. This tube tearing is often (though not always) a symptom of one or more motor mounts that are on their way out.
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it's happening on the other bank but just not to the extent of setting a code or if the problem is really localized to bank 1.
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He already said he found a torn intake tube. It was likely setting both codes.
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