If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
|
#1
|
|||
|
|||
Fuel system too lean code-- last try
I have been getting an intermittent P0171 code, fuel system too lean, along
with a P0170 code, fuel compensation value exceeded the specified range. To prevent a barrage of useless follow-up questions, here are the specs of my car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and distributor cap. I don't know where to start to find the source of this problem. If it helps someone to pinpoint the problem, I have on one or two occasions smelled a fuel smell while the light was on, and have occasionally had some hesitation before accelerating from a dead stop (even catching and almost stalling once or twice). The car also occasionally shakes while driving at a normal speed. Thanks for any suggestions about what to do. |
#2
|
|||
|
|||
jbourgeois wrote:
> I have been getting an intermittent P0171 code, fuel system too lean, along > with a P0170 code, fuel compensation value exceeded the specified range. To > prevent a barrage of useless follow-up questions, here are the specs of my > car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and > distributor cap. > > I don't know where to start to find the source of this problem. If it helps > someone to pinpoint the problem, I have on one or two occasions smelled a > fuel smell while the light was on, and have occasionally had some hesitation > before accelerating from a dead stop (even catching and almost stalling once > or twice). The car also occasionally shakes while driving at a normal > speed. > > Thanks for any suggestions about what to do. > > googling "p0171" got me: http://autorepair.about.com/library/faqs/bl903d.htm http://toyotaownersclub.com/forums/i...showtopic=9206 mass air flow sensor? |
#3
|
|||
|
|||
SoCalMike wrote:
> jbourgeois wrote: > >> I have been getting an intermittent P0171 code, fuel system too lean, >> along >> with a P0170 code, fuel compensation value exceeded the specified >> range. To >> prevent a barrage of useless follow-up questions, here are the specs >> of my >> car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and >> distributor cap. >> >> I don't know where to start to find the source of this problem. If it >> helps >> someone to pinpoint the problem, I have on one or two occasions smelled a >> fuel smell while the light was on, and have occasionally had some >> hesitation >> before accelerating from a dead stop (even catching and almost >> stalling once >> or twice). The car also occasionally shakes while driving at a normal >> speed. >> >> Thanks for any suggestions about what to do. >> >> > googling "p0171" got me: > > http://autorepair.about.com/library/faqs/bl903d.htm > http://toyotaownersclub.com/forums/i...showtopic=9206 > > mass air flow sensor? id run a couple tanks of fuel cleaner, look into seeing if the mass air flow sensor is cleanable, reset the code. do you use gas from a reputable station? |
#4
|
|||
|
|||
Thanks, this is the kind of reply I was hoping for. The fuel that I use is
from either BP or Shell. Ironically, the problem started only AFTER I first used a fuel injector cleaner a couple months ago. Does anyone know how to find and clean the Mass Air Flow sensor on a 1998 Honda Accord? "SoCalMike" > wrote in message news > SoCalMike wrote: > > jbourgeois wrote: > > > >> I have been getting an intermittent P0171 code, fuel system too lean, > >> along > >> with a P0170 code, fuel compensation value exceeded the specified > >> range. To > >> prevent a barrage of useless follow-up questions, here are the specs > >> of my > >> car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and > >> distributor cap. > >> > >> I don't know where to start to find the source of this problem. If it > >> helps > >> someone to pinpoint the problem, I have on one or two occasions smelled a > >> fuel smell while the light was on, and have occasionally had some > >> hesitation > >> before accelerating from a dead stop (even catching and almost > >> stalling once > >> or twice). The car also occasionally shakes while driving at a normal > >> speed. > >> > >> Thanks for any suggestions about what to do. > >> > >> > > googling "p0171" got me: > > > > http://autorepair.about.com/library/faqs/bl903d.htm > > http://toyotaownersclub.com/forums/i...showtopic=9206 > > > > mass air flow sensor? > > > id run a couple tanks of fuel cleaner, look into seeing if the mass air > flow sensor is cleanable, reset the code. > > do you use gas from a reputable station? |
#5
|
|||
|
|||
jbourgeois wrote: > > Thanks, this is the kind of reply I was hoping for. The fuel that I use is > from either BP or Shell. Ironically, the problem started only AFTER I first > used a fuel injector cleaner a couple months ago. > > Does anyone know how to find and clean the Mass Air Flow sensor on a 1998 > Honda Accord? I could be wrong, but I think you will have a very hard time finding a mass air flow sensor on that car. Most Honda's use Manifold Absolute Pressure sensors instead. The MAP sensor is typically located on top of the throttle body, but I have never heard of a MAP sensor that needs cleaning. Some engines us a MAF (mass air flow) sensor to directly measure the mass air flow, on Honda engines the ECU calculates the mass air flow based on the output from the Manifold Absolute Pressure sensor, the Intake Air Temperature sensor and the Throttle Position Sensor. One possible cause of a "too lean" code is a leak in the exhaust system, upstream of the oxygen sensor. If you have an exhaust leak, you will both get exhaust leaking out and fresh air going into the exhaust system. Fresh air going in will cause the oxygen sensor to sense oxygen in the exhaust, thus making the ECU believe the mixture is lean. Another thought is that if the fuel pressure is too low (failed pump or failed fuel pressure regulator) the injectors may not be able to inject enough fuel, even if left open for the maximum amount of time available. This would cause a lean condition as well. Let us know what you find out! |
#6
|
|||
|
|||
I did finally end up changing the fuel pressure regulator and rerouting the
vacuum hoses, as suggested in this thread. There was water in the regulator, causing a lean condition. The repair seems to have solved the problem. "Randolph" > wrote in message ... > > jbourgeois wrote: > > > > Thanks, this is the kind of reply I was hoping for. The fuel that I use is > > from either BP or Shell. Ironically, the problem started only AFTER I first > > used a fuel injector cleaner a couple months ago. > > > > Does anyone know how to find and clean the Mass Air Flow sensor on a 1998 > > Honda Accord? > > I could be wrong, but I think you will have a very hard time finding a > mass air flow sensor on that car. Most Honda's use Manifold Absolute > Pressure sensors instead. The MAP sensor is typically located on top of > the throttle body, but I have never heard of a MAP sensor that needs > cleaning. > > Some engines us a MAF (mass air flow) sensor to directly measure the > mass air flow, on Honda engines the ECU calculates the mass air flow > based on the output from the Manifold Absolute Pressure sensor, the > Intake Air Temperature sensor and the Throttle Position Sensor. > > One possible cause of a "too lean" code is a leak in the exhaust system, > upstream of the oxygen sensor. If you have an exhaust leak, you will > both get exhaust leaking out and fresh air going into the exhaust > system. Fresh air going in will cause the oxygen sensor to sense oxygen > in the exhaust, thus making the ECU believe the mixture is lean. > > Another thought is that if the fuel pressure is too low (failed pump or > failed fuel pressure regulator) the injectors may not be able to inject > enough fuel, even if left open for the maximum amount of time available. > This would cause a lean condition as well. > > Let us know what you find out! |
#7
|
|||
|
|||
SoCalMike wrote:
> jbourgeois wrote: > >> I have been getting an intermittent P0171 code, fuel system too lean, >> along >> with a P0170 code, fuel compensation value exceeded the specified >> range. To >> prevent a barrage of useless follow-up questions, here are the specs >> of my >> car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and >> distributor cap. >> >> I don't know where to start to find the source of this problem. If it >> helps >> someone to pinpoint the problem, I have on one or two occasions smelled a >> fuel smell while the light was on, and have occasionally had some >> hesitation >> before accelerating from a dead stop (even catching and almost >> stalling once >> or twice). The car also occasionally shakes while driving at a normal >> speed. >> >> Thanks for any suggestions about what to do. >> >> > googling "p0171" got me: > > http://autorepair.about.com/library/faqs/bl903d.htm > http://toyotaownersclub.com/forums/i...showtopic=9206 > > mass air flow sensor? afaik, honda don't use air flow mass sensors - they use pressure sensors & an electronic map of the differential between manifold pressure & atmosphere for whichever motor it is. that code is covered in http://www.alldata.com/TSB/24/982426AX.html which leads to: http://www.hondalac.com/service/Bulletins/x00-018e.pdf replace regulator & vacuum hoses. |
#8
|
|||
|
|||
Before I replace vacuum hose and fuel regulator, I need to know if the O2
sensor might be the problem. Does anyone know how to check that? Does a faulty or "lazy" O2 sensor seem like a possible cause for the system too lean code? "jim beam" > wrote in message news:1110057641.58f56630a503c7d86ca290cf490b466f@t eranews... > SoCalMike wrote: > > jbourgeois wrote: > > > >> I have been getting an intermittent P0171 code, fuel system too lean, > >> along > >> with a P0170 code, fuel compensation value exceeded the specified > >> range. To > >> prevent a barrage of useless follow-up questions, here are the specs > >> of my > >> car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and > >> distributor cap. > >> > >> I don't know where to start to find the source of this problem. If it > >> helps > >> someone to pinpoint the problem, I have on one or two occasions smelled a > >> fuel smell while the light was on, and have occasionally had some > >> hesitation > >> before accelerating from a dead stop (even catching and almost > >> stalling once > >> or twice). The car also occasionally shakes while driving at a normal > >> speed. > >> > >> Thanks for any suggestions about what to do. > >> > >> > > googling "p0171" got me: > > > > http://autorepair.about.com/library/faqs/bl903d.htm > > http://toyotaownersclub.com/forums/i...showtopic=9206 > > > > mass air flow sensor? > > afaik, honda don't use air flow mass sensors - they use pressure sensors > & an electronic map of the differential between manifold pressure & > atmosphere for whichever motor it is. > > that code is covered in > http://www.alldata.com/TSB/24/982426AX.html > which leads to: > http://www.hondalac.com/service/Bulletins/x00-018e.pdf > > replace regulator & vacuum hoses. > |
#9
|
|||
|
|||
jbourgeois wrote:
> "jim beam" > wrote in message > news:1110057641.58f56630a503c7d86ca290cf490b466f@t eranews... > >>SoCalMike wrote: >> >>>jbourgeois wrote: >>> >>> >>>>I have been getting an intermittent P0171 code, fuel system too lean, >>>>along >>>>with a P0170 code, fuel compensation value exceeded the specified >>>>range. To >>>>prevent a barrage of useless follow-up questions, here are the specs >>>>of my >>>>car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and >>>>distributor cap. >>>> >>>>I don't know where to start to find the source of this problem. If it >>>>helps >>>>someone to pinpoint the problem, I have on one or two occasions smelled > > a > >>>>fuel smell while the light was on, and have occasionally had some >>>>hesitation >>>>before accelerating from a dead stop (even catching and almost >>>>stalling once >>>>or twice). The car also occasionally shakes while driving at a normal >>>>speed. >>>> >>>>Thanks for any suggestions about what to do. >>>> >>>> >>> >>>googling "p0171" got me: >>> >>>http://autorepair.about.com/library/faqs/bl903d.htm >>>http://toyotaownersclub.com/forums/i...showtopic=9206 >>> >>>mass air flow sensor? >> >>afaik, honda don't use air flow mass sensors - they use pressure sensors >>& an electronic map of the differential between manifold pressure & >>atmosphere for whichever motor it is. >> >>that code is covered in >>http://www.alldata.com/TSB/24/982426AX.html >>which leads to: >>http://www.hondalac.com/service/Bulletins/x00-018e.pdf >> >>replace regulator & vacuum hoses. >> > > > Before I replace vacuum hose and fuel regulator, I need to know if the O2 > sensor might be the problem. Does anyone know how to check that? Does a > faulty or "lazy" O2 sensor seem like a possible cause for the system too > lean code? > i believe you usually get too rich in that situation. if it were my car, and there was a t.s.b. for exactly the problem i was experiencing, i'd be inclined to foillow the t.s.b.'s service procedure /before/ trying to chase anything else. |
#10
|
|||
|
|||
o2 sensors can fail in either direction, lean or rich
-- Stephen W. Hansen ASE Certified Master Automobile Technician ASE Undercar Specialist "jim beam" > wrote in message news:1110427276.a12680bb94f8fd03af6c1aa7d246717b@t eranews... > jbourgeois wrote: >> "jim beam" > wrote in message >> news:1110057641.58f56630a503c7d86ca290cf490b466f@t eranews... >> >>>SoCalMike wrote: >>> >>>>jbourgeois wrote: >>>> >>>> >>>>>I have been getting an intermittent P0171 code, fuel system too lean, >>>>>along >>>>>with a P0170 code, fuel compensation value exceeded the specified >>>>>range. To >>>>>prevent a barrage of useless follow-up questions, here are the specs >>>>>of my >>>>>car: 1998 Honda Accord LX, 4-cylinder, 123k. New spark plugs and >>>>>distributor cap. >>>>> >>>>>I don't know where to start to find the source of this problem. If it >>>>>helps >>>>>someone to pinpoint the problem, I have on one or two occasions smelled >> >> a >> >>>>>fuel smell while the light was on, and have occasionally had some >>>>>hesitation >>>>>before accelerating from a dead stop (even catching and almost >>>>>stalling once >>>>>or twice). The car also occasionally shakes while driving at a normal >>>>>speed. >>>>> >>>>>Thanks for any suggestions about what to do. >>>>> >>>>> >>>> >>>>googling "p0171" got me: >>>> >>>>http://autorepair.about.com/library/faqs/bl903d.htm >>>>http://toyotaownersclub.com/forums/i...showtopic=9206 >>>> >>>>mass air flow sensor? >>> >>>afaik, honda don't use air flow mass sensors - they use pressure sensors >>>& an electronic map of the differential between manifold pressure & >>>atmosphere for whichever motor it is. >>> >>>that code is covered in >>>http://www.alldata.com/TSB/24/982426AX.html >>>which leads to: >>>http://www.hondalac.com/service/Bulletins/x00-018e.pdf >>> >>>replace regulator & vacuum hoses. >>> >> >> > Before I replace vacuum hose and fuel regulator, I need to know if the >> O2 >> sensor might be the problem. Does anyone know how to check that? Does a >> faulty or "lazy" O2 sensor seem like a possible cause for the system too >> lean code? >> > i believe you usually get too rich in that situation. if it were my car, > and there was a t.s.b. for exactly the problem i was experiencing, i'd be > inclined to foillow the t.s.b.'s service procedure /before/ trying to > chase anything else. > |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Fuel system for Bank One too Lean code | jbourgeois | Honda | 5 | March 3rd 05 01:16 AM |
rec.autos.makers.chrysler FAQ, Part 3/6 | Dr. David Zatz | Chrysler | 0 | February 18th 05 05:33 AM |
Failed Smog Check 1981 Trans AM | TheSmogTech | Technology | 0 | January 30th 05 04:16 PM |
96 coupe 3.8 with code "P1151" | Chuck | Ford Mustang | 2 | January 1st 05 06:07 PM |
rec.autos.makers.chrysler FAQ, Part 1/6 | Dr. David Zatz | Chrysler | 10 | December 2nd 04 05:19 AM |