Oxygen Sensor?

[aeathb]

I have 40k miles on my 08 4runner and today I had the check engine light come on along with the vsc and Trac. I went to Autozone and I'm getting a p0031 and p0015 code. The p0031 is Bank 1 Sensor 1, and p0015 is bank 2 sensor 1. They are both showing faulty 02 sensor and or a poor electrical connection. The 4runner isn't running rough at idle or at speed; the only side effect is the dash lights coming on. I have tried searching for threads and its not my gas cap, I unplugged the battery terminals, and I pulled the fuses. The dealer wants to charge a lot of $$$ and I have a hard time believing that the 02 sensor is gone at 40k? The only thing I haven't done is checked the EFI relay because I have no clue where that's at; I tried searching for pictures of the location and couldn't find it. Thanks in advance.

 

[aeathb]

Update;
So I went to the dealer today and they said both 02 sensors are throwing. The service manager said "I have never heard of this happening on a newer car like yours." Price; $517 for parts, $180 for labor. Here is the thing I don't understand. When I asked the manager for symptoms of 2 faulty sensors he said low gas mileage, and reduced power. He also said if I unplug my battery, the car will have no codes to run off of and it will stall within 2 minutes. I am getting no reduced gas mileage, the v8 runs as quick as ever, and yesterday I unplugged my battery for an hour while I went and ran errands in the other car, yet, the car still works like normal.......Does anyone have any thoughts??

 

[CJ3Flyr]

No suggestions...


Are they going to try to charge you for the repair?

 

[aeathb]

No suggestions...


Are they going to try to charge you for the repair?

$700 consisting of $520 for the parts and $180 for the switch out. I have no clue how they can find anyone who sells o2 sensors for 260 a piece. I am 3K miles over the parts warranty (3 year 36K) so I am thinking I am just going to drive it untill something happens (hopefully drive train) then they can fix it. Other than that, I don't think there is much else to do....

 

[Acidmeld]

They are air/fuel ratio sensors, not o2 sensors. They are much more sensitive, accurate and expensive. They provide faster feedback to the ecm.

Their sensitivity is the problem. Lots of things can make them go bad. If you've run e85 thru that would ruin them. Even if youve gotten regular gas at a good station you can still get gas that has more than the max 10% allowed.

Something to check would be your battery. The battery supplies source voltage to the a/f sensor. If the voltage fluxuates too much itll throw false codes. If your battery test marginal it can cause this.

Both sensors dont go bad by themselves though. They need to be acted on by an outside source.

Hope this helps.

 

[aeathb]

They are air/fuel ratio sensors, not o2 sensors. They are much more sensitive, accurate and expensive. They provide faster feedback to the ecm.

Their sensitivity is the problem. Lots of things can make them go bad. If you've run e85 thru that would ruin them. Even if youve gotten regular gas at a good station you can still get gas that has more than the max 10% allowed.

Something to check would be your battery. The battery supplies source voltage to the a/f sensor. If the voltage fluxuates too much itll throw false codes. If your battery test marginal it can cause this.

Both sensors dont go bad by themselves though. They need to be acted on by an outside source.

Hope this helps.

Yea I know what you mean there. I know its not the gas because there is a non-ethanol fuel station near me (I have to pull a few strings for that one) but the voltage might be the problem. :thanks: again!

 

[CJ3Flyr]

$700 consisting of $520 for the parts and $180 for the switch out. I have no clue how they can find anyone who sells o2 sensors for 260 a piece. I am 3K miles over the parts warranty (3 year 36K) so I am thinking I am just going to drive it untill something happens (hopefully drive train) then they can fix it. Other than that, I don't think there is much else to do....

Emissions warranty duration is different I think... You problem is an emission control component. Here's a summary to read before you re-read the warranty that came with the vehicle http://ema-online.org/files/ToyotaWarrantyPolicy.pdf

 

[Iowa4Runner]

They are air/fuel ratio sensors, not o2 sensors. They are much more sensitive, accurate and expensive. They provide faster feedback to the ecm.

Their sensitivity is the problem. Lots of things can make them go bad. If you've run e85 thru that would ruin them. Even if youve gotten regular gas at a good station you can still get gas that has more than the max 10% allowed.

Something to check would be your battery. The battery supplies source voltage to the a/f sensor. If the voltage fluxuates too much itll throw false codes. If your battery test marginal it can cause this.

Both sensors dont go bad by themselves though. They need to be acted on by an outside source.

Hope this helps.

I don't mean to be a jerk and pick on you, but where are you getting this information? Even if the '08 4Runner uses wideband sensors in the exhaust system, they're still O2 sensors. Wideband sensors really do sense O2 and provide a proportional signal to the ECU vs. the rich/lean (2 discrete conditions) signal from a traditional O2 sensor.

Voltage fluctuations (that are caused by the battery) seem extremely unlikely to be the cause of the O2 sensor failure. Charging systems have come a long way since the 1970's Army jeeps that drove around with their lights all the time.

The fuel might very well be the cause of this. I've never heard of ethanol causing O2 sensor failures, I've run E10 in my 4Runner for 6 years and have never had a CEL/MIL. While E85 may not be recommended for use in Toyotas, I’ve not aware of how it would damage O2 sensors. Lead on the other hand, is a certified O2 sensor killer. I'm not sure what strings the OP had to pull to get non-ethanol fuel, but I wonder if he/she ended up with some fuel with lead in it or other contaminates. I know leaded fuel is hard to find in 2010, but there are still places that sell it. I know because I bought some high octane leaded gas to run in my motorcycle to diagnose a suspected spark knock problem.

 

[Acidmeld]

Its not what the a/f sensor and o2 sensor detect, its how. They both detect the o2 level, however they use different internal materials and give different voltage output readings.

Ethanol is one of the primary reasons these sensors go bad. E85 burns at a higher temp and will quickly overheat both types of sensor. A/f sensors are especially affected due to their sensitivity. The quality control in the oil industry is horrible and the fact that e10 is delivered with a max of 10% does not mean it gets to your tank that way.

System voltage is not regulated by the charging system. It is regulated by the battery. The charging system only controls the max voltage output by the alternator. The battery controls the voltage fluxuations going to the ecm. Then the ecm controls the 5v source to the sensors. The more the battery changes the more the source input changes and then the output of the sensor changes. A good battery regulates better.

As for where i learned this, i am a toyota master tech, not just some newbie. Thanks for listen and again i hope this helps.

 

[aeathb]

Today I learned after replacing both o2 sensors that the problem isn't that the o2 sensors are broken, it is that the computer isn't communicating with the sensors. Good news is my mechanic didn't charge me for the sensors, but the next step is making sure all the wiring is solid, and if that doesn't work sending it down to the stealership to get the computer reprogrammed. I'm not sure what is wrong at this point but it is surly out of my league of DIY(ing). Also, as my mechanic showed me, there are slight misfires that you can feel by touching the car. They aren't audible, but you can feel that the timing is off. The weird thing is that the car isn't throwing codes for the misfires..... not sure why. If anything any of you might think would be overlooked, suggestions are greatly welcomed.

 

[aeathb]

Emissions warranty duration is different I think... You problem is an emission control component. Here's a summary to read before you re-read the warranty that came with the vehicle http://ema-online.org/files/ToyotaWarrantyPolicy.pdf

Yea I thought the 02 sensors were under 8/80; so did my mechanic and the sales manager at the dealership...I guess not. I looked in the manual as well as called "Toyota Warranty Helping" and everyone told me "3/36."

 

[lVlAXX]

Let me add to the post with this. Today I started up my '03 v6 and the VSC , VSC Trac off, and ABS lights came on and i could not shift out of park. I finally yanked the gear shift and got it into drive (lights still on) drove to school looked up on this site a few things, push the button in front of the gear shift so i could shift it now and lights shut off after a few seconds. SOOO... is this fixed now or do i get to look forward to this again? FYI i have cleaned my MAF sensor and have a K&N air filter (saw these suggestions from previous post)

 

[Acidmeld]

Let me add to the post with this. Today I started up my '03 v6 and the VSC , VSC Trac off, and ABS lights came on and i could not shift out of park. I finally yanked the gear shift and got it into drive (lights still on) drove to school looked up on this site a few things, push the button in front of the gear shift so i could shift it now and lights shut off after a few seconds. SOOO... is this fixed now or do i get to look forward to this again? FYI i have cleaned my MAF sensor and have a K&N air filter (saw these suggestions from previous post)

Sounds like maybe a brake switch (controls the shift lock) but you should have the codes checked.

 

[aeathb]

Sounds like maybe a brake switch (controls the shift lock) but you should have the codes checked.

x2
My friend was having the same problem on a different car and it was brake related as well. If it was the pump or what that broke, I cannot remember.

 

[Iowa4Runner]

Its not what the a/f sensor and o2 sensor detect, its how. They both detect the o2 level, however they use different internal materials and give different voltage output readings.

Ethanol is one of the primary reasons these sensors go bad. E85 burns at a higher temp and will quickly overheat both types of sensor. A/f sensors are especially affected due to their sensitivity. The quality control in the oil industry is horrible and the fact that e10 is delivered with a max of 10% does not mean it gets to your tank that way.

System voltage is not regulated by the charging system. It is regulated by the battery. The charging system only controls the max voltage output by the alternator. The battery controls the voltage fluxuations going to the ecm. Then the ecm controls the 5v source to the sensors. The more the battery changes the more the source input changes and then the output of the sensor changes. A good battery regulates better.

As for where i learned this, i am a toyota master tech, not just some newbie. Thanks for listen and again i hope this helps.

You're really are a Toyota master technician? Seriously? Holy cow. I've never felt better about not buying the extended warranty for a vehicle.

 

[Acidmeld]

Why would i care about extended warranties. I hate them. They pay half the labor they should and generally screw everyone involved. Btw, If ive said anything inaccurate please correct me. Ive tried to be as specific as possible to help someone understand what could be wrong with their vehicle. If im wrong prove it, dont just call me a liar.

 

[Iowa4Runner]

Why would i care about extended warranties. I hate them. They pay half the labor they should and generally screw everyone involved. Btw, If ive said anything inaccurate please correct me. Ive tried to be as specific as possible to help someone understand what could be wrong with their vehicle. If im wrong prove it, dont just call me a liar.

Despite how it may appear, I'm not intending this to be a personal attack on you but...

1. I didn't call you a liar.
2. Your opinion of extended warranties is irrelevant in the context of this thread.
3. E85 does not burn at a higher temp than gasoline. Google it.
4. What makes you think quality control in the oil industry is horrible? Phase separation is the most likely cause of quality problems in ethanol blends and is the result of poor storage conditions provided by the reseller or end user. I've run cars for 10 years on E10 fuel and have never had an O2 sensor failure. How do you explain that?
5. Oxygen sensors - They all measure O2 and they all provide A/F ratio information to the ECU. If you want to get technical on the subject, explain the difference between wideband and narrow band sensors.
6. Voltage regulation - This might be semantics, but to say the system voltage is not regulated by the charging system is just plain wrong. Alternators use a voltage regulator to control the field current to the rotor and maintain a specified system voltage, which is about 14V. I've run my 4runner with the battery disconnected, and the voltage remained at 14.0 - 14.1 volts. If the battery was the primary element of voltage regulation, this would be impossible. Sure, with a good battery you'll have a cleaner power system, but the steady state, average system voltage is 100% the product of the alternator / voltage regulator and NOT the battery.

 

[lVlAXX]

right.... anyway my car did it again after not driving it for a day and the last time it did it (whatever day i posted) i had not driven it for a day that time either. My buddy said his lexus would show some lights on his car when the alternator was going bad, like the car was shutting down non essential items to get the engine to start...so maybe the alternator??

 

[Acidmeld]

right.... anyway my car did it again after not driving it for a day and the last time it did it (whatever day i posted) i had not driven it for a day that time either. My buddy said his lexus would show some lights on his car when the alternator was going bad, like the car was shutting down non essential items to get the engine to start...so maybe the alternator??

Your alernator wont cause a problem with the shift interlock. Youll have a completely dead battery before it affects that system.

 

[Acidmeld]

Iowa i apologize i was a bit oversensative. People dont usually contradict me. I beleive i wasnt specific enough on a few things.

You are correct that the E85 itself burns colder, however the lean condition it causes in the combustion chamber makes the temp rise considerably higher. The temp in the chamber is much higher as well as the gases being exhausted. The wideband sensor and the o2 sensor are very similar just a few differences. The o2 sensor outputs an analog signal to the ecm. The a/f sensor sends a digital signal. O2 sensors simply use a resistor to change the input 5v signal, whereas the a/f uses the resistor to turn the signal on/off at the signal voltage. This creates a faster input to the ecm because the ecm then doesnt have to change the analog signal to a digital signal.

The sensors also run at different temps. O2 runs at 750F A/f runs at 1200F. This is acheived by using less insulation on the electrode. This lack of insulation also makes it more susseptable to damage from increased exhaust temps.

When i wrote oil industry i was refering to the entire process from well to pump. Stations like bp and exxon-mobil get their gas straight from their own company and have fairly high storage standards. Most other stations (i.e. pumpers, spinx, the secondary market stations down here) get their oil from those same companies but have much lower standards for storage and transport. Water intrusion and ethanol seperation are much more prevalant at those stations.

As for the voltage regulation, the alternator is a big controller once the vehicle is running. The battery regulates the voltage at all times especially when ignition is first turned. This is an important fact because most o2 sensor and a/f sensor codes are detected in the first 2-5 seconds after turning the ig1 relay on. That is when the ecm does its self check of the a/f and o2 sensors.

As far as you never having a problem with your a/f sensensors its probably because your 2004 v8 uses o2 sensors front and rear. The V6 of that year uses a/f sensors front and o2 rear. It also could be the stations up there have higher quality control standards down here. Since i work at the dealership i see alot more of these problems than most people are aware of. We deal with this problem quite often in the southern states although i saw it much more rarely when i was working in wisconsin.