Hi Guys,

I've spent a ton of money trying to fix 2 CEL codes (P2A00 and P1172) with no luck - was wondering if somebody here might be able to help. I have a stock 2007 Honda Fit LX with 125,000km on it. I'll try to keep my story as concise as possible:

1) After initially getting the fault codes, I got an NTK oxygen sensor from Partsource and replaced the front one. I cleared the code, and it came back on after 5-10 minutes of driving.

2) I was told it can sometimes takes months for the car to "re-balance" after installing an O2 sensor, and the light may turn off then. I waited 6 months before deciding that's not the case here.

3) I took the car to a knowledgeable Honda mechanic (not the dealer). He ran me $200 in diagnostics to determine the oxygen sensor is working properly, but the computer is not. He gave me a technical service bulletin titled "MIL is on with DTC P1172 or P2A00" and suggested I get the computer updated at the dealership as outlined in the TSB:

http://www.driveaccord.net/forums/at...8&d=1207174855

4) Went to the dealership and had to pay $100 to update the computer according to the TSB. They cleared the light, and it came back on again after 5-10 minutes of driving. It did say in the TSB that you should replace the O2 sensor AFTER the computer update, but I don't want to buy the part again, especially when my mechanic ran diagnostics on it to find out it's working fine.

Has anybody else replaced non-OEM oxygen sensors themselves and had problems with them? Any suggestions on what to do next?

Thanks in advance!

 

Go buy an OE Bosch oxygen sensor.

You've spent all this time and money trying to get the computer to accept a non-factory part and you are surprised that it won't work?

And whoever told you to "re-balance" the sensor is either misguided or intentionally feeding you a line of BS.

You have to calibrate your O2's once before install and that is it.

Save yourself further time money and frustration and just get the OE part.

 

Any other suggestions besides buying another oxygen sensor and hoping it works? I was told NTK is a good brand, and the diagnostics showed it's working fine - I'm going to pull it out and test it myself to confirm, but I don't think it's the oxygen sensor. Also, My OEM oxygen sensor was a Denso - wouldn't getting a Bosch do the same thing as getting an NTK?

Thanks.

 

Go get the OE part, regardless.

They are going to have discreet differences in output is the point I am trying to convey.

And my sensor is a Bosch.. either way Bosch and Denso are the two must trusted for Nernst Cell sensors.

Why are you going out of your way and through this much time and money to make a non OE part work? The NTK sensor can function properly and still not send the signal the ECU is looking for.

 

I completely agree - hind sight is always 20/20 - I wouldn't have gone through this pain if I had known how sensitive the ECU would be... live an learn.

However, buying the OEM after all of this is my last resort - what if that doesn't fix the problem? I appreciate your opinion, but came here to see if anybody had some insight on other problems that might be tripping these codes.

Thanks again for your posts.

 

Best of luck, sir.

Let us know what you find.

Cheers.

 

I came across your post while googling about a similar problem with my 2005 Honda Accord. It started with a DTC of P0135 (O2 Sensor Heater Malfunction). I replaced the O2 sensor with a Bosch O2 sensor P/N 15400, which is a Honda OEM fitment. After driving only a few miles I got a DTC of P2A00 (O2 Sensor Range/Performance Problem). (The P0135 disappeared.) I'm reluctant to replace the O2 sensor again, as

1. I know it is as good as anything Honda sells;
2. I know it is in excellent condition; and
3. not taking quality into account, most modern O2 sensors are electrically equivalent.

The Honda Service Manual gives a detailed description of testing O2 sensor functionality by:

• Holding the engine speed at 3000 rpm in Park or Neutral until the radiator fan comes on, then letting it idle;
• Test driving with engine coolant temperature at more than 70ºC;
• Drive with A/T at D, or M/T in 3rd;
• Vehicle speed at 41 km/h or more;
• Engine speed at 3250 rpm or less;
• Then driving with throttle completely opened for 5 secs, followed by slowing down with throttle completely closed from an engine speed of 1600 rpm.

AND AT THIS POINT I'M ONLY HALF/WAY THRU THE DIRECTIONS! I hate to do all this with a scan tool in my lap.

The Honda Manual suggests that poor electrical connections between the O2 sensor and the ECM is a major cause of this problem.

BTW, I'm running open loop and my mileage has dropped by 25%. I'm also running rich (because of open loop) and that's not good for the cat convertor. I've got to get this thing fixed.

How did your problems with DTCs of P1172 and P2A00 resolve themselves?

 

Waiting six months was not a good idea. With DTCs of P1172 or P2A00 the engine runs "open loop," with pre-set values for injector pulse length. The short and long term fuel trims remain at 0%. Your engine was running rich. I bet you were getting low gas mileage.

Consider yourself lucky. BMW and Mercedes dealers charge about $300 to re-flash the ECU.

Yes, me, with a Bosch 15400. (The OEM sensors of most Hondas are Denso.)

Pack the connector between the sensor and the terminal from the ECU with dielectric grease. Most likely you have a bad connection between the AF sensor and the ECU.

 

On my 08 FIT the 02 sensor went first and then the check engine light came on again soon afterwards. I replaced the OTHER 02 sensor, called "Air/Fuel Mixture Sensor" in the exhaust manifold, and the codes have remained cleared. Both sensors were NTK and replaced with NTK from Honda, and both were crazy expensive. They look pretty much identical and it didn't surprise me thast they burned out at just about the same time. I had the intake manifiold off when I replaced the upper one, not sure I could have reached it otherwise. Look for my project post coming soon for photos

 

I'm starting to think Honda made a lemon when they made the FIT my 2009 Honda Fit sucks gas like a 3.0 liter Audi. And know-one seems to know why. I cleaned the injectors replaced the air-filter and baby the car I never push it hard ,it only has 27000 km on it why its getting terrible mileage is a mystery.

 

I was also getting P2A00 and P1172 codes in my 2008 fit. Replaced the Exhaust manifold Air Fuel sensor (front oxygen sensor) with a Bosh15260 that was mail ordered for around $180, same as the old one. Was a little tricky to replace due to space and the connector clip had to be released on both sides. Heating the car up helped in loosening up the old sensor, as well as a 22mm box wrench. Car only had 50k on it. Old sensor had a coating of black carbon on it, looks like i need to add a cleaner to fuel once in a while. Bad sensor never affected the mileage, stayed around 33 and that's ok since i drive half city half highway.

 

i had the P2A00 code also and i changed it with the oem one and good to go. My code showed up around 60k but i was in the mountains so i couldnt get it checked and fixed but once i got home i went to my local advance auto parts and i got it checked out. before it cleared itself (i dunno how) but i got the code and then around 105k the code came back so i changed the sensor. strange how it cleared itself before and i passed emissions then after the emissions it came back hahahahaha

 

I can tell you that most repair facilities in my area... including, obviously, Honda... will not replace your 02 sensors unless they are OEM Honda parts. They say they have had too many problems with the after-market stuff and refuse to go through with the complaint hassles whenever a customer had them installed. My suggestion with the O2 sensors is to go ONLY OEM. It may cost more initially, but its worth it. And, I'm not the type who would normally say that... I always try other brands after some research.

 

Sometimes the problem isn't caused by an aftermarket sensor.... they work well!
I would suggest to check the valve clearance too.....

 

i have teh p2a00 and 1172 codes right now, as well

i pulled my sensor yesterday and it was NOT black....at all...it had a fine gray color to it....

and what would valve clearance do to set these codes? I mean...did you just over hear it somewhere...and then you repeated it with no basis for why? i can only assume as much since you ended it with "....." and gave no effort to provide an explanation.

 

I thought the same thing when I read that.... along with the aftermarket O2 sensors..."they work well."

Valve clearance has absolutely nothing to do with these codes.

 

I gave you a suggestion! If you don't find it usefull it doesn't matter.
But I would recommend you to study the valve overlap before writing that valve clearance has absolutely nothing to do with these codes.

 

I HAVE read about these codes... the DO NOT have anything to do with the valve...period. Why don't you learn to read about the codes, yourself.

 

hi i have a 2002 honda fit, after changing wheel bearings abs light comes on amber, remains even after cleaning the sensors, now the drive light on dashboard flashes green even when it is put in 2nd gear, any suggestions as to the problem

 

I can read the codes very well, believe me!
I would like you to understand that 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.
This is only a possibility..
You should also check other things:
Fuel pressure
Fuel injector
Intake air leaks
o2 sensor etc...

with a proper scan software it's very easy to determine the problem.[/quote]