P0130, P0133, O2 Replace? MPG Hog?

[DIY_Apprentice]

Hey everyone.

I recently replaced my Thermostat because it was stuck open and causing errors. Now those have been fixed, but I noticed that my mpg was still bad, the car is still driving fine, but today on my way to work the CEL came back on. I scanned the codes and now I have a P0130 and P0133 which both relate to the O2 Sensor B1S1. Is this a situation I should just replace the sensor? Or could it be something else? Also, could this be the reason for my poor gas milage? Lastly, I saw there was a Downstream O2 Sensor Replace DIY but I don't think this is that one. Is there a DIY for the B1S1?

Here is the Freeze Frame for the code.

[DIY_Apprentice]

Anybody? Any suggestions would be helpful.

[JT_3K]

Sorry if I'm stating the obvious but I'd have said that idle looks low - I'd expect it to be 750-850. Also, it shows to be running rich which could be caused by any number of things (including the sensor) but will definately cause poor mileage.

Can't speak for Camry specific issues as of yet (I've only had one for a week) but general tech - If the sensor's out the ECU doesn't know how the gasses leaving the engine are and runs it rich to keep it going regardless of the efficiency in a really basic kind of 'limp home' system. Assuming you have the 5S-FE, there is a section in the official service manual available here on page EG1-231 that talks you through testing the sensor. However, for £40, it may just be worth buying a new one.

Good luck & let us know how you get on

[fenixus]

yeah, with those errors pointing at faulty o2 sensor circuit I would simply swap it out with new NTK/Denso part

also it might be something about wiring, a short causing circuit to stay open or something (circuit error), but since you also have code complaining on slow response from that sensor, then i would simply swap it out with new one. federal is cheap (~$80 shipped new NTK off amazon, OEM part). it's an easy job to do, you just need to borrow an o2 sensor socket from local autozone, it takes less than 10 mins usually.

http://www.ngksparkplugs.com/part_fi...uv/default.asp
to get NTK part number for your ride, then look for it on amazon or ebay. you may also find new Denso sensors cheap on ebay.

use www.toyodiy.com to get the factory part number.

[hill8570]

Hmmmm. I really hate to shotgun parts, but if the upstream (B1S1) sensor has never been replaced, it might be worth doing. No guarantee that will fix the problem 'tho -- might just be shooting the messenger. That low idle is slightly strange, but it's only 50 rpm below spec, so it may not mean much. When's the last time you changed out your air filter and cleaned the IAC valve?

If you reset the ECU (to clear trims back to zero), can you plot the output of B1S1 after she's warmed up and idling?

[DIY_Apprentice]

I don't believe the part has been replaced, I am second owner. I believe that my idle usually sits around 700 rpm but what could cause low idle, the air filter and IAC valve? I personally have not fixed either one and I do not even know what the IAC valve is. I can check the air filter tonight. I am using freeware software, so it does not do datalogging.

Fen, thanks for the part info 78 at amazon is pretty good.

Still not sure on how to actually replace the b1s1 I will keep looking in the service manuals.

Thanks.

[DIY_Apprentice]

think I found it under remove exhaust manifold EM-33.

[fenixus]

Originally Posted by DIY_Apprentice

I don't believe the part has been replaced, I am second owner. I believe that my idle usually sits around 700 rpm but what could cause low idle, the air filter and IAC valve? I personally have not fixed either one and I do not even know what the IAC valve is. I can check the air filter tonight. I am using freeware software, so it does not do datalogging.

Fen, thanks for the part info 78 at amazon is pretty good.

Still not sure on how to actually replace the b1s1 I will keep looking in the service manuals.

Thanks.

try cleaning IAC valve (through Throttle Body) just as described here, easy:
How to: Cleaning Throttle Body -4 Cylinder Engines- With Pictures

it won't heal the error code, but smooth-en the idle speed. all you need to replace the upstream o2 sensor is the o2 sensor socket and a torque wrench.

you can borrow OEM o2 sensor socket set from local Autozone, part number 27110:
http://www.autozone.com/autozone/cat...&brandName=OEM

you can get a cheap click-stop torque wrench 3/8'' drive (5-80ft-lbs range) from Harbor Freight Tools @ $15.99.

I don't remember the torque for o2 socket, but as far as i remember it was 33ft-lbs per NTK installation note. it was somewhere in FSM too. job is pretty straight forward, unplug sensor, then using above tools remove the old one and install new one in same spot, then re-connect. 10 mins tops

[DIY_Apprentice]

Fen,

Thanks for all the info. One last thing, was there supposed to be a link after

just as described here, easy:

???

I have a torque wrench and possibly a oxygen socket actually, have to check. I will check more stuff tonight and possibly order as well.

[fenixus]

Originally Posted by DIY_Apprentice

Fen,

Thanks for all the info. One last thing, was there supposed to be a link after



???

I have a torque wrench and possibly a oxygen socket actually, have to check. I will check more stuff tonight and possibly order as well.

LOL sorry, forgot to paste the link and then went out to lunch. updated post above.

cheers.

[JT_3K]

If you reset the ECU (to clear trims back to zero), can you plot the output of B1S1 after she's warmed up and idling?

+1!

think I found it under remove exhaust manifold EM-33

Yeah but the test instructions may be more help first on EG1-231

Don't forget to let us know if it worked

[DIY_Apprentice]

No issue with the missing link. That looks like something I will do this weekend. Depending on whether I order a new O2 Sensor or not, I will let you all know how it turns out. Thanks again!

[fenixus]

good luck!

... and don't give up ... i know that from exp that tracking down root cause of fuel trims is a real PITA. at some point you need to start swapping some things. it's always better to have a "fresh" upstream o2 sensor. those guys usually last up to 100k miles, but they can become slow much earlier than that.
usually they only reflect the condition like a mirror (or bring the news to ECU like a messenger), but with your error codes i think your sensor is simply dying.

it would be nice to see a graphical representation of that sensor readings on a warmed up car. not sure if you can achieve that with freeware obd2 though.

[DIY_Apprentice]

So I figured I would respond since I finally did what I said I would do like 3 weeks ago. I cleaned the throttle body, but fortunately/unfortunately it was already super clean so cleaning it again didn't make much difference in performance. I measured my idle speed and I sit right around 680 - 700 RPM. Next I replaced my oxygen sensor, old one did look really crappy when it came out, all discolored and whatnot, so I hope that the NTK one I replaced it with will fix my CEL issue. I drove it the day I fixed it and today to work without incident. Hopefully this will continue. Thanks to Everyone for their Help.