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Hey so i have big problem with my car
Its a 2004 Civic SI, 2.0L Engine (k20a3) hatchback.Im getting P0171 Code, P1298 code.
There is big LAG in acceleration, mostly after shifting, low rpms
Gas mileage is pretty bad, about 15 MPG
Battery check light all the time on
Smell gas outside and inside carWhen i start the car, it always revs around 1600rpm for 10min
Very often the revs jumping on idle, 750 -> 1100 -> 800 -> 1000 etc, every few seconds
Acceleration LAG is much bigger and worse when its hot outside, in chilly night driving it have much more power and smaller lag.When im checking with my OBD2 Scanner, my car all the time switching between OL -> CL -> OL -> CL
every second like crazy, doesnt matter car is warm or cold, its on idle or running 2000rpm or under high load.I was in 3 different places to fix my car, everywhere they spent 4 hours searching the problem, and always saying “WE DON’T KNOW” at the end,
billing me 500$ anyway. So i spent like 1500$ for diagnostics where they found nothing.
I can’t go to mechanic again, and pay 500$ for “i don’t know whats wrong” again.I have few videos here, i speak Polish on the videos so you may not understand but its simple:
This one is shift from 2nd to 3rd and gas pedal to the floor
This one is reading live data from OBD2
LITTLE HISTORY HERE:
I bought this car in november, with check engine light on, battery light on, srs light on.
So i bring it to “good” mechanic, for a biggest tune up to check and do everything.
I replaced both o2 sensors, but DTC was still on, and mechanic said he don’t know why battery light is on.So next i took it to different mechanic, and they spent 5 hours to checking the car, no vacumm leak, no exhaust leak,
check timing, inigtion, fuel pump, fuel pressure, injectors, sensors etc
They found NOTHING, and they said it must be a bad ECU.So i took the car to honda dealer, they were looking 3.5 hours, and checking again fuel pump, leaks, vacumm, timing, fuel…blablabla
and they found NOTHING and also suggested a bad ECU.So i got a new ECU, honda dealer programmed immo etc, and with new ECU battery check light is still on, always.
Also check engine light came on after 10min drive.All the DTC codes in history when i own the car
– P0171 System Too Lean (Bank 1)
– P0134 Oxygen 02 Sensor Circuit No Activity Detected (Bank I Sensor 1)
– P0135 Oxygen O2 Sensor Heater Circuit Malfunction (Bank1, Sensor1)
– P2A00 Oxygen O2 Sensor Circuit Range/Performance Bank 1 Sensor 1
– P1298 Electric Load Detector Circuit High VoltageNew parts replaced in history of the car.
(NEW) Upstream sensor DENSO 234-9004
(NEW) Downstream sensor DENSO 234-4122
(NEW) Serpentine belt
(NEW) OEM ELD (Electronic Load Detector) 8255-S5A-003
(NEW) OEM RELAY ASSY., FUEL PUMP (5P) OEM 39794-S5A-003
(NEW) OEM RELAY ASSY., ENGINE CONTROL MODULE (4P) OEM 39794-S5A-901
(NEW) OEM RELAY ASSY., POWER (4P)
(NEW) OEM PCV VALVE 17130-PRB-A01
(USED) OEM MAP SENSOR 37830-PGK-A01
(USED) OEM ECU 37820-PNF-A11
(NEW) Most of fuses
(NEW) Cat Converter
(NEW) NGK Spark PlugsI dont have any electrical skills, so every proposition i gonna ask my friends to do it.
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It’s doubtful that an internet forum can diagnose your car after it has already been looked at by 3 shops, but I’m sure we will all try to offer the best advice we can. First, was power and ground verified to the O2 sensor heaters? I know you replaced the sensors, but you did not indicate that the wiring integrity going to the sensors was verified (after all, you did get the P0135 code). By wiring integrity, that means checking for open/short and that the wire can carry current. An intact wire can show continuity but not necessarily carry enough current due to high resistance caused by rust or corrosion. The heaters need to work or this will cause the OL/CL switching back and forth, especially on the upstream sensor (again you got the code for this). Second, I would check the proper operation of the engine coolant temperature sensor. It is a thermistor, which means it should change resistance with the temperature. If this resistance is out of range, this can cause strange things with the ECM. Test, don’t guess. Parts should always be tested before replacement. Most everything can be tested. Also, don’t discount the possibility of a new part being bad out-of-the-box. New parts installed should always be tested to verify the fix once a defective part has been identified.
Yes, what i read is, car should start with OL then should switch to CL and use a primary o2 sensor, but my car goin back to OL like it don’t get reading from o2 sensor.
I did a test for primary sensor
Unplugged – got P1166 code in few seconds
Plugged bad sensor – got P1166 code in few seconds
Plugged new sensor – very rarely P0134 code once a 2 weeks~The code coming all the time is P0171 too lean, and P1298 ELD.
– same thing with eld, replaced for brand new, but maybe wire is shorted somewhereWhat about battery light on? Because is there all the time, even when there is no stored or pending DTCs
What i gonna do is check all the wires and harness for now i think.
[strike]A few questions to make sure I understand where you are currently:
What codes does your car currently have?
Briefly, what problem(s) do you notice with how the engine runs?[/strike]
Ok, I’ve re-read the posts and think I understand better now.
P1298 looks like a Honda-specific code: “Electric Load Detector Circuit High Voltage”
https://www.autocodes.com/p1298_honda.html
I would address that problem first because it sounds like it could trigger other problems by fooling the ECU.
After a very brief Google search, I found this:
It appears the fix was to replace the electric load detector (ELD). There may be a diagnostic procedure somewhere, but I haven’t looked for it.
Was the ELD ever checked and/or replaced?After control-f on this thread, I see the ELD was replaced.
Does your car have any after-market electronics of any kind installed on it?
Also, who replaced the ELD? Are you sure a new unit was used? I ask because of the last post in this thread:
I had the same problem: P1298 ELD problem. I have an 01 Civic LX and had a 2003 LX parts car. I replaced the ELD in my car from the parts car and to no avail! Still the P1298 code check engine light. I called Honda Parts and was told it was probably a defective ELD. He said the defective part covered years 2001-03, and that is probably why the 03 one didn’t work. He said they had a new updated part. I bought the new ELD for around $30 and installed it in the under-the-hood fuse box. And “YES”, the new part worked. No check-engine-light the past few weeks. So, if your getting a p1298 code, please don’t put yourself through the time-consuming trouble of checking all the electric circuits. Just get a new ELD from honda and your problem will be solved.
https://honda-tech.com/forums/tech-misc-15/p1298-error-no-solutions-found-2538384/
[quote=”Mlyno” post=187862]Yes, what i read is, car should start with OL then should switch to CL and use a primary o2 sensor, but my car goin back to OL like it don’t get reading from o2 sensor.
I did a test for primary sensor
Unplugged – got P1166 code in few seconds
Plugged bad sensor – got P1166 code in few seconds
Plugged new sensor – very rarely P0134 code once a 2 weeks~The code coming all the time is P0171 too lean, and P1298 ELD.
– same thing with eld, replaced for brand new, but maybe wire is shorted somewhereWhat about battery light on? Because is there all the time, even when there is no stored or pending DTCs
What i gonna do is check all the wires and harness for now i think.[/quote]
Have the battery load tested, and have the alternator tested too. A bad battery and/or alternator can wreak havoc with the computer.
Battery and alternator tested, with results from honda dealer attached in 1st post.
Also few other mechanic checked battery/alt and said its good.ELD was replaced by myself, first i got used ELD from junkyard, installed and nothing changed, then i went to honda dealer and bought brand new oem part, installed by myself again and nothing changed.
battery check light on the cluster is a different problem, because even if there is no P1298 i always have battery check light, and thats only the light.
After replacing a ECU, battery light didn’t came off even for 1 second.
I live in winnipeg where we have -40 celsius at winter, i dont have block heater, i never ever had problem with start my carPrevious owner had a amp, subwoofer and some audio installed. There is nothing left, only wires
[quote=”Mlyno” post=187879]Previous owner had a amp, subwoofer and some audio installed. There is nothing left, only wires[/quote]
Perhaps that is a clue to the battery light. There may be a fault in the electrical system due to this wiring job. Since I cannot inspect it, I cannot say for sure, but in the past I have seen all sorts of weird things happen due to electrical system alterations while installing aftermarket accessories.As for the engine performance, the dealer ticket in your first post says that the injectors are dumping fuel while the A/F is reporting a lean condition. Plus you say you can smell a strong raw fuel smell. That may indicate an exhaust restriction, possibly a plugged catalytic converter, even though you don’t have a code for it. Codes don’t always get thrown depending on other conditions.
[quote=”cap269″ post=187884]As for the engine performance, the dealer ticket in your first post says that the injectors are dumping fuel while the A/F is reporting a lean condition. Plus you say you can smell a strong raw fuel smell. That may indicate an exhaust restriction, possibly a plugged catalytic converter, even though you don’t have a code for it. Codes don’t always get thrown depending on other conditions.[/quote]
I had same idea about clogged cat converter, so as i also wrote in 1st post, i replaced cat converter for new one like two weeks ago, nothing changes with performance and gas smell after replace.
So today is hot outside 25 celsius and car drive like nightmare.
Big lag in acceleration, doesn’t matter 2nd or 3rd gear. Even 1st gear is worse
When i release gas pedal the car don’t slowing smoothly, just rough.Also, when i first time started the car today, and as i said its hot outside, the cooling fan came on after 30 seconds, working for 5 seconds, turn off, came on again, turn off again. Everything on IDLE, and while changing ON/OFF cooling fan, the revs also jumps and falls (about 300rpm up or down)
That’s a pretty good clue. Try this as an experiment: remove the cooling fan relay and run the car to see what happens, especially if it makes the battery light go out, then report back with your findings.
What a nightmare.
It certainly sounds like an electrical problem, not just a sensor problem.
One thing to investigate is why the alternator light remains on.
If the trouble is a failing diode that allows excessive AC current into the electrical system, this can wreak havoc on sensors–even damaging them.
Excellent article about that here, with how to test info:
http://www.pvv.org/~syljua/merc/TooSeptST07.pdf
The dealer does not seem to have performed thorough alternator/charging system diagnostics–only a basic output test to see if there’s enough voltage at idle.
More testing is ideal.The best writeup on a very similar problem with the oxygen sensors is linked below and you will find helpful info such as to check the A/F sensor relay, how to test the heated oxygen sensor circuit and this:
“One likely cause of the trouble, is grease inside the under hood fuse box connector melting due to high engine compartment temperatures. The liquefied grease then travels down the engine wiring harness and makes its way into the A/F ratio sensor’s four-pin connector, taking out the sensor in the process. Replacing the A/F ratio sensor and installing a new sub-harness kit (Call Honda for the applicable parts) to route the grease away from the connector is the recommended fix.”
https://answers.yahoo.com/question/index?qid=20150115190413AAYBTIuI wonder if the problem is , in fact melting grease in the underhood fuse box and if it has shorted out several circuits.
An auto electric shop, rather than anywhere else, would be where to invest diagnostic dollars, if your friends cannot help you to fix the problem.
See if autozone has electrical diagrams for your car. You have to join their mailing list, IIRC, to access the free info databases.
A google search might also yield the schematics you need .It appears as if you’re in the 204 area code, so am I.
Feel free to shoot me a PM, on the profile page, if you’re in the peg I still have access to a previous employers indentifix account if you want to come by and give it a go.
Thanks for all the replies.
I did a “longer” obd2 test during normal drive by my GF, and what i see on the scanner is:
– o2 sensor should read 0.1V – 0.9V but most time its stuck at 0,005V
and even if sometimes voltage go up, its always less than 0.45V which mean lean all the time
thats why my car go to closed loop, but return back to open loop because of “bad” sensor. and this repeat every second.
– other thing is LONGFT1 is stuck as you see in video 7-8%, SHRTF1 go most time 46% i don;t know its normal?My spark plugs, my o2 sensor, exhaust is covered black, thats mean rich.
My “bad” o2 sensor tells my ECU wrong reading, so ECU tell me LEAN, and try to put more fuel because it thinks its lean, thats why i have so bad mileage (15mpg) and gas smell.I found place where they do a wiring and wiring issues, its 85$ hour labour, and gonna take few hours, but i think its neccessery for me to DO IT.
Also going to replace coolant temperature sensor.Im correct with that?
You can’t judge the fuel trims while this main issue with the O2 sensor exists. The O2 is putting out constant lean, the computer is adding fuel, so the STFT shows this. The STFT probably maxes out at the number you’re reading. So, it is normal considering the existing problem, but isn’t normal for a properly running engine. What you want is: TFT (total fuel trim) = LTFT + STFT, with TFT to be around 0% (ideal). TFT up to +/- 10% is considered acceptable. Don’t replace ANYTHING unless it has been TESTED and found to be FAULTY. The landfill is brimming with perfectly good sensors that have been replaced without testing. You had a code for O2 heater circuit malfunction. If the O2 sensor is not hot it will not work properly. I would expect a “bad” sensor to be stuck at around 450mV. Also, “stuck at 0.005V” means that the sensor is sending a constant lean signal, and isn’t switching because the stream is still lean. Power and ground to the O2 heater needs to be verified, and a resistance check of the O2 heater coil needs to be done, before condemning the sensor. The coolant temperature sensor can also be tested with a coffee cup of hot water, a coffee cup of ice water, a thermometer to measure the water temperature, and an ohmmeter to measure the sensor’s resistance. In an earlier response I posted an attachment that has the resistance chart for good ECT values at various temperatures. Test, don’t guess. The wiring shop may be a good idea, but a better idea is to go there with the knowledge of what’s wrong, even if they do all the fixing. Otherwise, you could come away with a very large bill and still have issues. By the way, your symptoms indicate to me that there is more than one issue, so fixing one thing may not necessarily cure all.
Yes, im not going to replace any parts for now.
“bad o2 sensor” i mean, bad wiring to o2 sensor, of course there is few % chance, brand new sensor from the box is faulty too.
Saying about black covered plugs, o2 sensor i just wanted to add, thats mean rich.
Plugs replaced week ago, o2 sensors 2 months ago, and cat converter 2 weeks ago.Also i forget about important thing i tested with old cat converter. I just removed primary o2 sensor, leaving a hole before cat converter. And of course car was loud as f**k but performance was hundred times better! no perfect or good yet, but much better. Thats why i was thinking my cat converted is clogged and i replaced it. I also noticed a rotten eggs smell after aggresive driving.
Im not cheap about this car, i just want to fix it, im not looking for cheap “replacement solutions”. It looks like i see 3 problems with electrical system:
– P1298 eld too high voltage (even after new eld)
– Battery check light always on
– few codes and issues with o2 sensorAnd as i said, im not able to do/check any electrical stuff as i have 0 experience and knowledge about that, thats why i gonna visit this wiring shop.
Is there anything important what i dont know but i should tell them?[quote=”Mlyno” post=187966] I found place where they do a wiring and wiring issues, its 85$ hour labour, and gonna take few hours, but i think its neccessery for me to DO IT.
Also going to replace coolant temperature sensor.
Im correct with that? [/quote]
[b]No. Not what I would do now
I wrote my reply before DaFirnz wrote his reply 4 posts above this one.
If I were you, I would definitely contact DaFirnz, (who is an experienced auto technician) and have him help you.
To contact him, scroll to his post and, on the left side where his username and picture are, click on MORE, then scroll down underneath Thank You Received: 205 and click on the box that allows you to contact him.
I think this is your wisest option.[/b][quote=”DaFirnz” post=187933] It appears as if you’re in the 204 area code, so am I.
Feel free to shoot me a PM, on the profile page, if you’re in the peg I still have access to a previous employers indentifix account if you want to come by and give it a go. [/quote]
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