O2 Sensor INfo

Received a check engine light today. I have an ODBII scanner on my phone with bluetooth. (wasn't sure if this thing would work and it actually did). I received an O2 Sensor out of range or catalytic converter running out of range. I reset the code and it hasn't reappeared yet (50 miles later). Question: Is it possible for an O2 Sensor to flake out temporary or is this just a symptom of a failing sensor that needs to be replaced? I was using my truck with a 10 foot util trailer, moving household appliances, goods, etc. to another storage unit. Unit was on the other side of the building, so I never got up over 5 MPH but was starting and stopping truck all day long. Could starting/stopping hauling with a 2,000 lb trailer load cause a sensor to show as failing or does that have nothing to do with it? Any advice greatly appreciated. Have had many Subaru Outbacks and know the O2 sensor issues with those vehicles well but first time on my Tacoma I have had an O2 check engine light come one.

 

I believe that it really has nothing to do with it at all, not an expert, just my opinion.

An O2 Sensor can give out at any time after only 1 year of driving a vehicle, after 5 years, 10 years, etc. so really if it's going to go out it will.

By chance did you put any type of fuel additive in your tank in the past few days or so ago? This has been known to cause the check engine light to appear and leads to either one of the two O2 sensors (Bank One or Bank Two) submitting a code? (even one of the two Ratio/Fuel Sensors as well)

If the Check Engine light (code) does not return, I wouldn't put much into it but it if does then I would recommend to replace it. (use either a Denso made O2 or an OEM and nothing else).

Good Luck and keep us posted on your results.

 

Thank you Tex-Tac. I was thinking there probably wasn't a correlation but I am by no means an auto mechanic. I haven't used any additives, etc. The only thing besides the trailer that was different was that I got stuck the previous day in really soft sand (my wife and I our building a home and I got a little to ambitious with going onto the building site ) and I used Four Low and did hit pretty high RPM's a few times. I know not great, but it got a way from me, trying to rock the vehicle out. Never red lined and only short period of time. It is a 2011 truck, so maybe it is just time. It did give me a code and I erased it . I am having a hard time on the o2 sensor purchase... They are listing Left, Right, then Downstream, etc. I think there is only 2 if I am correct? One downstream and one upstream which is called the Fuel/Ratio sensor? When looking at an auto parts store, they list several options, even the same brand both saying Left or Right and the price ranges from $90 to $200. I can't quite tell what the difference is? So I will call dealer on Monday to find out what the exact o2 sensor is. It looks easy to put in but the Fuel/Ratio looks hard to get to. So I will try the o2 first.

 

What was the exact code #. For a code to appear certain parameters have to be met as well as so many failed out of ranges. An Os sensor can be sluggish and not even set a code. But if it was the O2 sensor code that also deals with the catalytic converter efficiency you'll need to look at the pids and see what the primary O2 (before cat) and secondary O2 are reading. If they are the same reading more than likely a bad cat if the secondary is just stuck and not really moving at all from start up to warmed engine then more than likely a bad O2. Without actually seeing it for myself this is the best answer I can give you. Also if the cats are working the way they should the secondary O2 (cat monitors essentially) don't fluctuate in their readings a whole lot.

 

When you first checked your OBD II, what exactly did it give an indication of?.....meaning did it say something like...P0420 or P0430 code, Bank One Sensor One or Two..something like that?

If so, then click on this link and read the section that explains in more detail exactly what this means.

1GR-FE ENGINE CONTROL SYSTEM – SFI SYSTEM

SFI System P0420 P0430: http://www.customtacos.com/tech.old...06toyrm/06toypdf/06rmsrc/rm2006ta/0050034.pdf

Also click on the link below to see exactly where each Air/Fuel Ratio Sensor & O2 Oxygen Sensor is located at.

http://www.customtacos.com/tech.old...f/06toyrm/06toypdf/06rmsrc/rm2006ta/00500.pdf

As I previously mentioned, if you do buy replacements for either one, make sure they are either the Denso brand or OEM. The Denso brand is a bit cheaper than OEM Toyota brand which would be purchased directly from the dealership but sometimes we have no choice and have to buy from them.
You really don't have to the choice is yours and buy some other brand, such as Bosch, etc. Though I have read where individuals did buy some other brand only to remove them and replace them with either Denso brand or OEM because they started receiving the same codes as before.

The following link is a list of codes that you may receive: http://www.customtacos.com/tech.old...06toyrm/06toypdf/06rmsrc/rm2006ta/0050011.pdf

Make sure that when you do install them that they are installed correctly and either tighten down or properly torqued to the correct specifcations (32 to 35 ft-lbs. for either one)

If not then you will start receiving codes again.

Yes the Air Fuel/Ratio Sensors are the hardest to reach and replace!

(Now just a warning here. If by chance you replace either one or all four sensor's and have actually cleared all the codes previously stored in your ECU and have given enough time for all the new sensors to break in, etc. and start receiving codes again, then this means that the dreadful Catalyst Convert is going bad and needs to be replaced....and that my friend is freaking expensive!....so lets hope and pray that it's not)

Good luck and as before keep us posted on the outcome.

 

Hence why I suggested diagnosing first before just replacing the O2 sensors. If you correctly diagnose before replacing any parts saves time and $$$.

 

Thank for all the great info. I was able to find the original code, it was P0430. Am I nuts to think it might be fixed? After resetting I haven't had the check engine light come back on, have put on around 200 miles. I am going to assume that it is not fixed or was some freak reading but something else. Thank you for answering one of the questions I haven't been able to figure out, the amount of sensors. So there are a total of four then? That makes way more sense as to what I am seeing online at the parts store. Hoping that it is not the catalytic converter too.

 

That code if for Cat efficiency more than likely the cat had degraded and now needs replaced. But checking the rear O2 sensor readings will confirm.

 

ovrIndkull: If cat, is it correct that there are two? A left and a right? Was looking here: https://www.partsgeek.com/catalog/2..._manifold_with_integrated_catalytic_converter

 

P0430 has specific requirements to trigger and long drive intervals to trigger. It always comes back eventually.

It's only truly resolved if the drive cycle monitor is completed.

Most OBD scanners have monitor status indicators.

 

Left manifold, bank 2.

 

Bank 2

 

This^^^^^

There are also instructions in repair manuals of how to drive to get those drive conditions and cycles to trigger after the repair or to confirm if cleared previously

 

If a bad cat, can you replace just one at a time or are both needed?
Thank you in advance for your help.

 

Jinx

 

Excellent info,thank you and makes a lot of sense as to why it hasn't triggered yet.

 

You can just do the one that is bad. These are the cats that are attached to the manifolds not the ones in the y-pipe

 

I like to quote both for customers, I can usually tell by watching the data stream if the other cat is ready to fail.

Another option is an 02 simulator to eliminate the code, but thats a slippery slope haha.

 

Thank you. Would you recommend replacing the O2 sensor or is it actually doing it's job and reporting that the cat is bad? If it were a bad O2 sensor, would there be different symptoms. It is a 2011 with 160k on the motor. I bought used last year (Canadian owned truck) and I have no idea if they ever replaced the O2 sensors.

 

Yeah usually if one goes the other is not that far behind. Secondarily you may want to just freshen up the maint. on the truck if it's due a tune up etc. If the truck is running richer or leaner than it should this can cause cats to break down quicker than normal.