Hey Guys,

As a follow-up, I ended up taking the car to the dealer to replace the O2 sensor and clear the CEL for good. I suspected there was more wrong than just the sensor, and didn't want to gamble on the cost of another self-installed part that might not have fixed the problem.

The dealer gladly replaced the sensor for $445 ($285 for the part, $109 labour, $51 tax). I know that's an inflated cost for the part, but that's what you get with the dealer! I asked which sensor they installed, and they could only tell me "Genuine Honda, possibly Denso"... and I don't care to remove it to find out until it fails again down the road.

The problem is fixed and the CEL is cleared for good now.

Anyway, in hind sight, I should have installed a Denso sensor, and it likely would have fixed the problem. However, now that I know how sensitive the computer is to different oxygen sensors, I would recommend taking it to the dealer and paying the premium to ensure you're not wasting your time and money on a part that won't sync with your computer... who knows, even a mail-ordered Denso sensor might have had issues as well.

Hope this helps somebody out there in the same predicament.

 

Unfortunately, I figured, as I said before, that that was probably the problem. I've heard the story too many times to not repeat it here.

The crime is that the Honda dealers charge an outrageous price for that part. They probably make a killer profit. Also, the labor cost is ridiculous since the whole job won't take more than 10 minutes, but they will charge to the nearest hour.

I'm glad it finally worked out okay and will solve your problem.

 

are you fucjking kidding me?!?!

stop reading random things on the internet and thing making a story up in your head as to how they work.

 

I rewrite you the reason:
a wrong valve overlap allows unburned fuel out the exhaust or lean mixture (it depends..). The oxygen sensor reads the rich or the lean mixture and the computer attempts to adjust the fuel to air ratio.

Anyway I haven't read it on Internet... I've studied it! I don't know if you have ever studied mechanic...
I use two aftermarket sensors (ngk universal: 45 euro) without problems..... so if you like spending lots of money it's up to you.
...but use a proper language when you write.

 

It's also written in Honda manual!!!!

You won't find the generic P1172, but the specific P0172....
You only have to study, before talking or writing!!!

DTC Troubleshooting: P0171 (45-2), P0172 (45-1)

DTC P0171 (45-2): Fuel System Too Lean
DTC P0172 (45-1): Fuel System Too Rich
NOTE: If some of the DTCs listed below are stored at the same time as DTC P0171 and/or P0172, troubleshoot those DTCs first, then recheck for P0171 and/or P0172.

P0107, P0108: manifold absolute pressure (MAP) sensor
P0135: primary heated oxygen sensor (primary HO2S) (Sensor 1) heater

1. Check the fuel pressure.
Is fuel pressure OK?

YES - Go to 2.

NO - Check these items:

• If the pressure is too high, replace the fuel pressure regulator.n
• If the pressure is too low, check the fuel pump, the fuel feed pipe, the fuel filter, and replace the fuel pressure regulator.n

2. Start the engine. Hold the engine at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on.
3. Check the primary HO2S (Sensor 1) output with the HDS or the scan tool.
Does it stay at less than 0.3 V or more than 0.6 V?

YES - Replace the primary HO2S (Sensor 1).n

NO - Go to 4.

4. Turn the ignition switch OFF. 5. With a vacuum pump (A), apply vacuum to the evaporative emission (EVAP) canister purge valve (B) from the evaporative emission (EVAP) canister side.



ABDoes it hold vacuum?


YES - Go to 6.

NO - Replace the EVAP canister purge valve.n

6. Turn the ignition switch ON (II).
7. Check the manifold pressure with the HDS or the scan tool.
Does it indicate atmospheric pressure?

YES - Go to 8.

NO - Replace the MAP sensor.n

8. Start the engine.
9. Check the MAP sensor with the HDS or the scan tool.
Is a MAP of 40.0 kPa (300 mmHg, 12.0 in.Hg) or less indicated within 1 second after starting the engine?

YES - Check the engine valve clearance and adjust if necessary. If the valve clearance are OK, replace the injector.n

NO - Replace the MAP sensor.n

 

The original poster is asking about code P1172 which is an error specific to the O2 sensor, only. The P0172 code has nothing to do with this error... it has to do with the system being too rich. They are not related codes. You can't just change a number 1 to a number 0 and then diagnose a problem like that.

 

Holy Toledo, I just got back from the Honda dealer. $100 for a diagnostic and $350 to replace an oxygen sensor. I've only got 23,000 miles on my 2008 Fit Sport. Needless to say, I was surprised an oxygen sensor would even go out at this few a miles and then the price to diagnose and fix... yikes. Wish I could have diagnosed and fixed the problem myself like you are talking about here.

 

It's very difficult talking with you:
P1172 is a generic code that means out of range (high); if o2 signal is high (near to 1 volt) it means the fuel is rich! If lambda is out of range it means that o2 is too high or too low (P1171), simply!!! .... some dtc troubleshooting are universal, other are specific.... you should know this!
Of course they are different!
P0172 or P0171 are specific codes (when the fuel trim try to adjust the mixture...) that you can find in workshop manual (you won't find P1172, instead...because it it's supposed you are using the correct sensor)
There's also another possibility, in fact: maybe they have bought a wrong aftermarket o2 sensor, and that's why it didn't work....

If you need some more explanation feel free to ask.

 

I'll explain you something from old school: how to test your lambda sensor with a multimeter

Set a multimeter to the low reading ohms scale. Connect one lead of the multimeter to one black wire coming out of the sensor and the other multimeter lead to the other black wire, which consists of the heating element wires. Do not allow the meter leads to touch any other pin in the connector. Your reading should display about 12 ohms of resistance. A reading that exceeds 12 ohms or reads to infinity means that the sensor has failed.This can help to save your money...

$100 for a diagnostic is very much! You can buy

eBay Italia - Aste online e shopping a prezzo fisso

I use it with my laptop, my android phone and my double din autoradio (with android) too...

 

What I don't understand is why you attack me....
The purpose of the forum should be listening, learning, talking etc..
I haven't written wrong things, I only wrote things that, probably you didn't know...

Regarding the out of range of o2 sensor, for example, I could tell you how to change lambda range in the ecu, reprogramming it....
I only wrote that valve clearance may be responsable for lambda sensor errors....
I don't know if we are talking about original or modified cars. These are simply universal suggestions;
then if people can't understand problems because they haven't an obd scan software and hardware, honda dealers are very happy to help you.
I say again I use two aftermarket lambda sensors without problems....
Next time I'll keep my suggestion for me....

 

I just got back from spending $350 at the Honda dealer for a new oxygen sensor for my 2008 Honda Fit Sport with 23,000 miles on it. After expressing some disappointment for incurring this expense for my car with that few miles, I asked the service manager why or how this sensor could have gone so bad and what I can do to prevent this new sensor from also going out after 20,000 or so miles. He said to start buying more expensive gas at the better gas stations as they will help reduce carbon buildup. I've bought my gas at the moderately priced places for years and have never had an oxygen sensor problem and so the question for you the forum is this: Did what the service manager tell me have any merit? Or is he blowing smoke?

 

Crappy gas isn't any crappier than it's been in years. I have yet to have an O2 sensor fail me on any of the cars I've owned; Chevy,Dodge, Honda, Nissan, Toyota, and I've always bought the cheapest gas that I could find. All my cars have lasted to 200k with no engine or O2 problems.

 

cargirl He gave you a pat fallback answer, not wrong but not necessarily right either. 20K miles is quick and 'bad' fuel can do it... but other things could have been going on.

How did you know there was an issue? Did this come out of the blue? Drive-ability, starting problem, CEL coming on? How had it been running as you accelerated?

 

<<How did you know there was an issue? Did this come out of the blue? Drive-ability, starting problem, CEL coming on? How had it been running as you accelerated?>>

An engine light went on about two weeks ago. I checked the manual and it said that something was wrong with my emissions control system and to first check the fuel cap to make sure it was on tight. If that was the problem, it said the issue would resolve itself in a few days and the light would go back off. After a week, when the light never did go off, I ended up taking the car to the Honda dealer where they did a diagnostic test ($100) and determined I had a faulty oxygen sensor. Up until then, I didn't notice any difference in the way the car drove, but it did seem I wasn't getting as good gas mileage and mentioned this to the technician when I brought the car in for servicing. His thought was that gas mileage does go down in our Midwest winters and that a bad oxygen sensor could or could not be a contributor to the lower gas mileage.

 

In my opinion bad fuel can ruin the catalyst, but not the oxygen sensor, after only 20.000 miles...
Nowadays cars are very careful about emissions, but maybe your ecu had only an error stored about oxygen sensor; this didn't mean it should be changed...
It's more probably that cause of fuel or something else, ecu has tried to adjust the mixture outside its normal range, giving the error...
That's why anyone should have a scan software...

 

A bad O2 will certainly trip the CEL and kill MPG as well. Faulty O2's can intermittently trip the CEL under a strong acceleration with the engine just shy of warm-up, then clear themselves. I think they found the problem.

Good for you for understanding the role the gas cap might have played.

Winter blends will drop MPG as well, but not trip the CEL.

Something I'm not sure of is if the O2 sensor is considered part of the emissions warranty. I'm positive it'e been discussed before but don't know of conclusions/facts. 20K miles seems quick to me on the factory O2.

alf74 - an O2 sensor code is tripped by a voltage change at the sensor. If the fuel air ratio was part of the mix it would have it's own associated codes. Given the CEL was lit for a week says all codes would be available, current and history.

Having scan software is a benefit if your so inclined to understand it's depths. Diagnosing emission issues is a complicated process. With experience, many techs cut to the chase - they've been down the road before and 'know' what the problem is. It's what we pay them to do. Most of us are not that well versed.

But, having a code reader can help explain issues to that tech when you bring the car in.

Something that has never changed in diagnosing car performance is the drivers ability to accurately explain the issue. It's the life blood of the crew chief/driver relationship.

 

I recently purchased a 2008 fit Sport. There is an ongoing problem with the oxygen sensor. After reading through these posts, my guess is that the current O2 sensor is not compatible with the Honda fit, and that I need an OEM part. However, a mechanic told me that he suspected that there was a larger problem with the electrical system. Here is a timeline of events:

1. The previous owner had the O2 sensor fail last year. It was replaced with a third-party sensor by a neighbourhood mechanic.

2. Shortly after this, the engine light came on again. The diagnostic said the O2 sensor was defective. The previous owner took it back to the neighbourhood mechanic who was unable to fix the problem.

3. The car was put up for sale around this time. The seller was upfront about the defective O2 sensor, and told me that he was taking it into the Honda Dealership to be fixed.

4. On the day that the car was to have the O2 sensor fixed, I also had the dealership to an all-points check on the Honda Fit. The dealership charged $135 to recalibrate the sensor, and told me that there was nothing else wrong with the car. (The previous owner absorbed all these costs, and I bought the vehicle that day).

5. Later that day the engine light came back on. I made an appointment with the same Honda dealer to find out what the problem was. The dealer told me that the O2 sensor was defective and needed to be replaced. They wanted to charge me $460.00 to put in a new O2 sensor.

6. I phoned the previous owner, and found out that the O2 sensor in the fit was still under warranty. I took it back to the neighbourhood mechanic and he gave me a new O2 sensor and charged me $100.00 for labour. (This mechanic also told me that he suspected there was a larger electrical problem with the car).

7. After driving the car about 40 km the engine light in the vehicle came back on.

What are the chances that if I pay Honda $460.00 for a new OEM O2 sensor, that the engine light will still come back on because of this suspected 'larger electrical problem'?

Thanks in advance

 

But are we always talking about the same problem: P2A00 and P1172 ?
It seems that your o2 sensor is out of the range written in your Ecu....
so, in my opinion, the problem wouldn't seem to be changing it with a new one (original or aftermarket).
The solution could be reflashing your ecu (to change the lambda range), admitting you can find someone who can do it, or you could try with a Wideband Lambda/AFR (λ) controllers (I have never used it because I can reprogram Jazz's ecu by myself...)
Or maybe your ecu is damaged....
I asked my honda dealer and it said that this code doesn't exist on Italian Jazz model.... maybe because of different anti-pollution regulation

 

Tagged for interest.

 

There are two 02 sensors on the Fit. One is located on the exhaust manifold and the other is on the muffler. At 63K miles my secondary (muffler) one failed producing the code, and after replacing it and clearing the code by D/C the battery for 30 minutes, one week later my primary one failed, producing another check engine light. After replacing that one I have had no more codes. I used OEM NTK sensors but next time will order Denso sensors from Amazon.com for less expense and I think that Denso is the BEST for Japanese electrics. So you need to insure that both primary and secondary 02 sensors have been replaced. I also highly recommend Denso Long-Life Iridium plugs, and I am a Social Worker and do not work for Denso,.